pdf: Add entry and exit of annotation-mode

* Adds a new viewer element to host the Ink component. For now this is
  just a dummy implementation of the expected API allowing us to test
  entry/exit.
* `ContentController` is extended with load/unload
* `InkController` is added and made the current controller when in
  annotation mode, delegating behavior to the viewer-ink-host rather
  than plugin.
* The plugin interface is extended to allow the PDF to be saved and
  sent back regardless of whether the PDF has been modified.
* The loaded state of PDFViewer is centralized and exposed via the
  `loaded` property. This allows the switching logic and tests to wait
  for the mode switch to complete.

Bug: 902646
Change-Id: I2922cb121e510e9e84c21b75faddc48fa90a195c
Reviewed-on: https://chromium-review.googlesource.com/c/1368846
Commit-Queue: dstockwell <dstockwell@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#617686}

chrome/browser/resources/component_extension_resources.grd

@@ -119,6 +119,8 @@
         <include name="IDR_PDF_VIEWER_BOOKMARKS_CONTENT_JS" file="pdf/elements/viewer-bookmarks-content/viewer-bookmarks-content.js" type="BINDATA" />
         <include name="IDR_PDF_VIEWER_ERROR_SCREEN_HTML" file="pdf/elements/viewer-error-screen/viewer-error-screen.html" type="BINDATA" />
         <include name="IDR_PDF_VIEWER_ERROR_SCREEN_JS" file="pdf/elements/viewer-error-screen/viewer-error-screen.js" type="BINDATA" />
+        <include name="IDR_PDF_VIEWER_INK_HOST_HTML" file="pdf/elements/viewer-ink-host/viewer-ink-host.html" type="BINDATA" />
+        <include name="IDR_PDF_VIEWER_INK_HOST_JS" file="pdf/elements/viewer-ink-host/viewer-ink-host.js" type="BINDATA" />
         <include name="IDR_PDF_VIEWER_PAGE_INDICATOR_HTML" file="pdf/elements/viewer-page-indicator/viewer-page-indicator.html" type="BINDATA" />
         <include name="IDR_PDF_VIEWER_PAGE_INDICATOR_JS" file="pdf/elements/viewer-page-indicator/viewer-page-indicator.js" type="BINDATA" flattenhtml="true" />
         <include name="IDR_PDF_VIEWER_PAGE_SELECTOR_HTML" file="pdf/elements/viewer-page-selector/viewer-page-selector.html" type="BINDATA" />

chrome/browser/resources/pdf/BUILD.gn

@@ -10,6 +10,7 @@ group("closure_compile") {
     ":pdf_resources",
     "elements/viewer-bookmark:closure_compile",
     "elements/viewer-error-screen:closure_compile",
+    "elements/viewer-ink-host:closure_compile",
     "elements/viewer-page-indicator:closure_compile",
     "elements/viewer-page-selector:closure_compile",
     "elements/viewer-password-screen:closure_compile",

chrome/browser/resources/pdf/elements/viewer-ink-host/BUILD.gn

@@ -0,0 +1,14 @@
+# Copyright 2018 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//third_party/closure_compiler/compile_js.gni")
+
+js_type_check("closure_compile") {
+  deps = [
+    ":viewer-ink-host",
+  ]
+}
+
+js_library("viewer-ink-host") {
+}

chrome/browser/resources/pdf/elements/viewer-ink-host/viewer-ink-host.html

@@ -0,0 +1,13 @@
+<link rel="import" href="chrome://resources/html/polymer.html">
+
+<dom-module id="viewer-ink-host">
+  <template>
+    <style>
+      :host {
+        visibility: hidden;
+      }
+    </style>
+    [[dummyContent_]]
+  </template>
+  <script src="viewer-ink-host.js"></script>
+</dom-module>

chrome/browser/resources/pdf/elements/viewer-ink-host/viewer-ink-host.js

@@ -0,0 +1,49 @@
+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * Hosts the Ink component which is responsible for both PDF rendering and
+ * annotation when in annotation mode.
+ */
+Polymer({
+  is: 'viewer-ink-host',
+
+  properties: {
+    /** @private */
+    dummyContent_: String,
+  },
+
+  /** @private {?string} */
+  dummyFileName_: null,
+
+  /** @private {ArrayBuffer} */
+  dummyData_: null,
+
+  /**
+   * Begins annotation mode with the document represented by `data`.
+   * When the return value resolves the Ink component will be ready
+   * to render immediately.
+   *
+   * @param {string} fileName The name of the PDF file.
+   * @param {ArrayBuffer} data The contents of the PDF document.
+   * @return {!Promise} void value.
+   */
+  load: async function(fileName, data) {
+    this.dummyContent_ = `Annotating ${data.byteLength} bytes`;
+    this.dummyFileName_ = fileName;
+    this.dummyData_ = data;
+    this.style.visibility = 'visible';
+  },
+
+  /**
+   * @return {!Promise<{fileName: string, dataToSave: ArrayBuffer}>}
+   *     The serialized PDF document including any annotations that were made.
+   */
+  saveDocument: async function() {
+    return {
+      fileName: this.dummyFileName_,
+      dataToSave: this.dummyData_,
+    };
+  },
+});

chrome/browser/resources/pdf/elements/viewer-pdf-toolbar/viewer-pdf-toolbar.html

@@ -125,6 +125,7 @@
         <div id="buttons" class="invisible">
           <template is="dom-if" if="[[pdfAnnotationsEnabled]]">
             <paper-icon-button id="annotate" icon="pdf:create"
+                on-click="toggleAnnotation"
                 aria-label$="{{strings.tooltipAnnotate}}"
                 title$="{{strings.tooltipAnnotate}}">
             </paper-icon-button>
@@ -160,7 +161,7 @@
         </div>
       </div>
       <div id="progress-container">
-        <paper-progress id="progress" value="{{loadProgress}}"></paper-progress>
+        <paper-progress id="progress" value="[[loadProgress]]"></paper-progress>
       </div>
     </div>
   </template>

chrome/browser/resources/pdf/elements/viewer-pdf-toolbar/viewer-pdf-toolbar.js

@@ -9,7 +9,7 @@ Polymer({
     /**
      * The current loading progress of the PDF document (0 - 100).
      */
-    loadProgress: {type: Number, observer: 'loadProgressChanged'},
+    loadProgress: {type: Number, observer: 'loadProgressChanged_'},
 
     /**
      * The title of the PDF document.
@@ -36,6 +36,14 @@ Polymer({
      */
     opened: {type: Boolean, value: true},
 
+    /**
+     * Whether the viewer is currently in annotation mode.
+     */
+    annotationMode: {
+      type: Boolean,
+      notify: true,
+    },
+
     /**
      * Whether the PDF Annotations feature is enabled.
      */
@@ -44,11 +52,18 @@ Polymer({
     strings: Object,
   },
 
-  loadProgressChanged: function() {
-    if (this.loadProgress >= 100) {
-      this.$.pageselector.classList.toggle('invisible', false);
-      this.$.buttons.classList.toggle('invisible', false);
-      this.$.progress.style.opacity = 0;
+  /**
+   * @param {number} newProgress
+   * @param {number} oldProgress
+   * @private
+   */
+  loadProgressChanged_: function(newProgress, oldProgress) {
+    const loaded = newProgress >= 100;
+    const progressReset = newProgress < oldProgress;
+    if (progressReset || loaded) {
+      this.$.pageselector.classList.toggle('invisible', !loaded);
+      this.$.buttons.classList.toggle('invisible', !loaded);
+      this.$.progress.style.opacity = loaded ? 0 : 1;
     }
   },
 
@@ -126,6 +141,10 @@ Polymer({
 
   print: function() {
     this.fire('print');
+  },
+
+  toggleAnnotation: function() {
+    this.annotationMode = !this.annotationMode;
   }
 });
 })();

chrome/browser/resources/pdf/index.css

@@ -20,6 +20,7 @@ viewer-pdf-toolbar {
   z-index: 4;
 }
 
+viewer-ink-host,
 #plugin {
   height: 100%;
   position: fixed;

chrome/browser/resources/pdf/index.html

@@ -3,6 +3,7 @@
 <head>
   <meta charset="utf-8">
   <link rel="import" href="elements/viewer-error-screen/viewer-error-screen.html">
+  <link rel="import" href="elements/viewer-ink-host/viewer-ink-host.html">
   <link rel="import" href="elements/viewer-page-indicator/viewer-page-indicator.html">
   <link rel="import" href="elements/viewer-page-selector/viewer-page-selector.html">
   <link rel="import" href="elements/viewer-password-screen/viewer-password-screen.html">
@@ -38,6 +39,7 @@
 <script src="pdf_scripting_api.js"></script>
 <script src="chrome://resources/js/load_time_data.js"></script>
 <script src="chrome://resources/js/util.js"></script>
+<script src="chrome://resources/js/promise_resolver.js"></script>
 <script src="browser_api.js"></script>
 <script src="metrics.js"></script>
 <script src="pdf_viewer.js"></script>

chrome/browser/resources/pdf/pdf_viewer.js

@@ -125,9 +125,7 @@ function PDFViewer(browserApi) {
   this.isFormFieldFocused_ = false;
   this.beepCount_ = 0;
   this.delayedScriptingMessages_ = [];
-
-  /** @private {!Set<string>} */
-  this.pendingTokens_ = new Set();
+  this.loaded_ = new PromiseResolver();
 
   this.isPrintPreview_ = location.origin === 'chrome://print';
   this.isPrintPreviewLoadingFinished_ = false;
@@ -220,10 +218,12 @@ function PDFViewer(browserApi) {
   } else {
     this.plugin_.setAttribute('full-frame', '');
   }
+
   document.body.appendChild(this.plugin_);
 
   this.pluginController_ =
       new PluginController(this.plugin_, this, this.viewport_);
+  this.inkController_ = new InkController(this, this.viewport_);
   this.currentController_ = this.pluginController_;
 
   // Setup the button event listeners.
@@ -252,6 +252,8 @@ function PDFViewer(browserApi) {
         'print', () => this.currentController_.print());
     this.toolbar_.addEventListener(
         'rotate-right', () => this.currentController_.rotateClockwise());
+    this.toolbar_.addEventListener(
+        'annotation-mode-changed', e => this.annotationModeChanged_(e));
 
     this.toolbar_.docTitle = getFilenameFromURL(this.originalUrl_);
   }
@@ -472,6 +474,52 @@ PDFViewer.prototype = {
     }
   },
 
+  /**
+   * Handles the annotation mode being toggled on or off.
+   *
+   * @param {CustomEvent} e
+   * @private
+   */
+  annotationModeChanged_: async function(e) {
+    const annotationMode = e.detail.value;
+    if (annotationMode) {
+      // TODO(dstockwell): add assert lib and replace this with assert
+      if (this.currentController_ != this.pluginController_) {
+        throw new Error(
+            'Plugin controller is not current, cannot enter annotation mode');
+      }
+      // Enter annotation mode.
+      // TODO(dstockwell): set plugin read-only, begin transition
+      this.updateProgress(0);
+      // TODO(dstockwell): handle save failure
+      const result = await this.pluginController_.save(true);
+      // TODO(dstockwell): feed real progress data from the Ink component
+      this.updateProgress(50);
+      await this.inkController_.load(result.fileName, result.dataToSave);
+      this.currentController_ = this.inkController_;
+      this.pluginController_.unload();
+      this.updateProgress(100);
+    } else {
+      // Exit annotation mode.
+      // TODO(dstockwell): add assert lib and replace this with assert
+      if (this.currentController_ != this.inkController_) {
+        throw new Error(
+            'Ink controller is not current, cannot exit annotation mode');
+      }
+      // TODO(dstockwell): set ink read-only, begin transition
+      this.updateProgress(0);
+      // This runs separately to allow other consumers of `loaded` to queue
+      // up after this task.
+      this.loaded.then(() => {
+        this.currentController_ = this.pluginController_;
+        this.inkController_.unload();
+      });
+      // TODO(dstockwell): handle save failure
+      const result = await this.inkController_.save(true);
+      await this.pluginController_.load(result.fileName, result.dataToSave);
+    }
+  },
+
   /**
    * Request to change the viewport fitting type.
    *
@@ -559,9 +607,41 @@ PDFViewer.prototype = {
       this.metrics.onFollowBookmark();
   },
 
+  /**
+   * @return {Promise} Resolved when the load state reaches LOADED,
+   *     rejects on FAILED.
+   */
+  get loaded() {
+    return this.loaded_.promise;
+  },
+
+  /**
+   * Updates the load state and triggers completion of the `loaded`
+   * promise if necessary.
+   * @param {!LoadState} loadState
+   * @private
+   */
+  setLoadState_(loadState) {
+    if (this.loadState_ == loadState) {
+      return;
+    }
+    if ((loadState == LoadState.SUCCESS || loadState == LoadState.FAILURE) &&
+        this.loadState_ != LoadState.LOADING) {
+      throw new Error('Internal error: invalid loadState transition.');
+    }
+    this.loadState_ = loadState;
+    if (loadState == LoadState.SUCCESS) {
+      this.loaded_.resolve();
+    } else if (loadState == LoadState.FAILED) {
+      this.loaded_.reject();
+    } else {
+      this.loaded_ = new PromiseResolver();
+    }
+  },
+
   /**
    * Update the loading progress of the document in response to a progress
-   * message being received from the plugin.
+   * message being received from the content controller.
    *
    * @param {number} progress the progress as a percentage.
    */
@@ -577,7 +657,7 @@ PDFViewer.prototype = {
         this.passwordScreen_.deny();
         this.passwordScreen_.close();
       }
-      this.loadState_ = LoadState.FAILED;
+      this.setLoadState_(LoadState.FAILED);
       this.isPrintPreviewLoadingFinished_ = true;
       this.sendDocumentLoadedMessage_();
     } else if (progress == 100) {
@@ -586,12 +666,14 @@ PDFViewer.prototype = {
         this.viewport_.position = this.lastViewportPosition_;
       this.paramsParser_.getViewportFromUrlParams(
           this.originalUrl_, this.handleURLParams_.bind(this));
-      this.loadState_ = LoadState.SUCCESS;
+      this.setLoadState_(LoadState.SUCCESS);
       this.sendDocumentLoadedMessage_();
       while (this.delayedScriptingMessages_.length > 0)
         this.handleScriptingMessage(this.delayedScriptingMessages_.shift());
 
       this.toolbarManager_.hideToolbarsAfterTimeout();
+    } else {
+      this.setLoadState_(LoadState.LOADING);
     }
   },
 
@@ -797,7 +879,7 @@ PDFViewer.prototype = {
         this.pluginController_.postMessage(message.data);
         return true;
       case 'resetPrintPreviewMode':
-        this.loadState_ = LoadState.LOADING;
+        this.setLoadState_(LoadState.LOADING);
         if (!this.inPrintPreviewMode_) {
           this.inPrintPreviewMode_ = true;
           this.isUserInitiatedEvent_ = false;
@@ -1003,7 +1085,8 @@ PDFViewer.prototype = {
    * Saves the current PDF document to disk.
    */
   save: async function() {
-    const result = await this.currentController_.save();
+    // TODO(dstockwell): Report an error to user if this fails.
+    const result = await this.currentController_.save(false);
     if (result == null) {
       // The content controller handled the save internally.
       return;
@@ -1057,10 +1140,77 @@ class ContentController {
 
   /**
    * Requests that the current document be saved.
+   * @param {boolean} requireResult whether a response is required, otherwise
+   *     the controller may save the document to disk internally.
    * @return {Promise<{fileName: string, dataToSave: ArrayBuffer}}
    * @abstract
    */
-  save() {}
+  save(requireResult) {}
+
+  /**
+   * Loads PDF document from `data` activates UI.
+   * @param {string} fileName
+   * @param {ArrayBuffer} data
+   * @return {Promise<void>}
+   * @abstract
+   */
+  load(fileName, data) {}
+
+  /**
+   * Unloads the current document and removes the UI.
+   * @abstract
+   */
+  unload() {}
+}
+
+class InkController extends ContentController {
+  /**
+   * @param {PDFViewer} viewer
+   * @param {Viewport} viewport
+   */
+  constructor(viewer, viewport) {
+    super();
+    this.viewer_ = viewer;
+    this.viewport_ = viewport;
+
+    /** @type {ViewerInkHost} */
+    this.inkHost_ = null;
+  }
+
+  /** @override */
+  rotateClockwise() {
+    // TODO(dstockwell): implement rotation
+  }
+
+  /** @override */
+  rotateCounterClockwise() {
+    // TODO(dstockwell): implement rotation
+  }
+
+  /** @override */
+  print() {
+    // TODO(dstockwell): implement printing
+  }
+
+  /** @override */
+  save(requireResult) {
+    return this.inkHost_.saveDocument();
+  }
+
+  /** @override */
+  load(filename, data) {
+    if (!this.inkHost_) {
+      this.inkHost_ = document.createElement('viewer-ink-host');
+      document.body.appendChild(this.inkHost_);
+    }
+    return this.inkHost_.load(filename, data);
+  }
+
+  /** @override */
+  unload() {
+    this.inkHost_.remove();
+    this.inkHost_ = null;
+  }
 }
 
 class PluginController extends ContentController {
@@ -1075,7 +1225,7 @@ class PluginController extends ContentController {
     this.viewer_ = viewer;
     this.viewport_ = viewport;
 
-    /** @private {!Map<string, Function>} */
+    /** @private {!Map<string, PromiseResolver>} */
     this.pendingTokens_ = new Map();
     this.plugin_.addEventListener(
         'message', e => this.handlePluginMessage_(e), false);
@@ -1162,13 +1312,30 @@ class PluginController extends ContentController {
   }
 
   /** @override */
-  save() {
-    return new Promise(resolve => {
-      const newToken = createToken();
-      this.pendingTokens_.set(newToken, resolve);
-      const force = false;
-      this.postMessage({type: 'save', token: newToken});
-    });
+  save(requireResult) {
+    const resolver = new PromiseResolver();
+    const newToken = createToken();
+    this.pendingTokens_.set(newToken, resolver);
+    this.postMessage({type: 'save', token: newToken, force: requireResult});
+    return resolver.promise;
+  }
+
+  /** @override */
+  async load(fileName, data) {
+    const url = URL.createObjectURL(new Blob([data]));
+    this.plugin_.removeAttribute('headers');
+    this.plugin_.setAttribute('stream-url', url);
+    this.plugin_.style.display = 'block';
+    try {
+      await this.viewer_.loaded;
+    } finally {
+      URL.revokeObjectURL(url);
+    }
+  }
+
+  /** @override */
+  unload() {
+    this.plugin_.style.display = 'none';
   }
 
   /**
@@ -1250,15 +1417,21 @@ class PluginController extends ContentController {
    * @private
    */
   saveData_(messageData) {
-    if (!(loadTimeData.getBoolean('pdfFormSaveEnabled')))
+    if (!(loadTimeData.getBoolean('pdfFormSaveEnabled') ||
+          loadTimeData.getBoolean('pdfAnnotationsEnabled')))
       throw new Error('Internal error: save not enabled.');
 
     // Verify a token that was created by this instance is included to avoid
     // being spammed.
-    const resolve = this.pendingTokens_.get(messageData.token);
+    const resolver = this.pendingTokens_.get(messageData.token);
     if (!this.pendingTokens_.delete(messageData.token))
       throw new Error('Internal error: save token not found, abort save.');
 
+    if (!messageData.dataToSave) {
+      resolver.reject();
+      return;
+    }
+
     // Verify the file size and the first bytes to make sure it's a PDF. Cap at
     // 100 MB. This cap should be kept in sync with and is also enforced in
     // pdf/out_of_process_instance.cc.
@@ -1275,6 +1448,6 @@ class PluginController extends ContentController {
       throw new Error('Not a PDF file.');
     }
 
-    resolve(messageData);
+    resolver.resolve(messageData);
   }
 }

chrome/browser/ui/webui/print_preview/print_preview_ui.cc

@@ -436,6 +436,10 @@ void SetupPrintPreviewPlugin(content::WebUIDataSource* source) {
   source->AddResourcePath(
       "pdf/elements/viewer-error-screen/viewer-error-screen.js",
       IDR_PDF_VIEWER_ERROR_SCREEN_JS);
+  source->AddResourcePath("pdf/elements/viewer-ink-host/viewer-ink-host.html",
+                          IDR_PDF_VIEWER_INK_HOST_HTML);
+  source->AddResourcePath("pdf/elements/viewer-ink-host/viewer-ink-host.js",
+                          IDR_PDF_VIEWER_INK_HOST_JS);
   source->AddResourcePath(
       "pdf/elements/viewer-page-indicator/viewer-page-indicator.html",
       IDR_PDF_VIEWER_PAGE_INDICATOR_HTML);

chrome/test/data/pdf/annotations_feature_enabled_test.js

@@ -2,6 +2,20 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+
+function contentElement() {
+  return document.elementFromPoint(innerWidth / 2, innerHeight / 2);
+}
+
+async function testAsync(f) {
+  try {
+    await f();
+    chrome.test.succeed();
+  } catch (e) {
+    chrome.test.fail(e);
+  }
+}
+
 chrome.test.runTests([
   function testAnnotationsEnabled() {
     const toolbar = document.body.querySelector('#toolbar');
@@ -10,4 +24,20 @@ chrome.test.runTests([
         toolbar.shadowRoot.querySelector('#annotate') != null);
     chrome.test.succeed();
   },
+  function testEnterAndExitAnnotationMode() {
+    testAsync(async () => {
+      chrome.test.assertEq('EMBED', contentElement().tagName);
+
+      // Enter annotation mode.
+      $('toolbar').toggleAnnotation();
+      await viewer.loaded;
+      chrome.test.assertEq(
+          'VIEWER-INK-HOST', contentElement().tagName);
+
+      // Exit annotation mode.
+      $('toolbar').toggleAnnotation();
+      await viewer.loaded;
+      chrome.test.assertEq('EMBED', contentElement().tagName);
+    });
+  }
 ]);

pdf/out_of_process_instance.cc

@@ -102,6 +102,7 @@ constexpr char kJSPrintType[] = "print";
 // Save (Page -> Plugin)
 constexpr char kJSSaveType[] = "save";
 constexpr char kJSToken[] = "token";
+constexpr char kJSForce[] = "force";
 // Save Data (Plugin -> Page)
 constexpr char kJSSaveDataType[] = "saveData";
 constexpr char kJSFileName[] = "fileName";
@@ -666,11 +667,17 @@ void OutOfProcessInstance::HandleMessage(const pp::Var& message) {
   } else if (type == kJSPrintType) {
     Print();
   } else if (type == kJSSaveType) {
-    if (!dict.Get(pp::Var(kJSToken)).is_string()) {
+    if (!(dict.Get(pp::Var(kJSToken)).is_string() &&
+          dict.Get(pp::Var(kJSForce)).is_bool())) {
       NOTREACHED();
       return;
     }
-    Save(dict.Get(pp::Var(kJSToken)).AsString());
+    const bool force = dict.Get(pp::Var(kJSForce)).AsBool();
+    if (force) {
+      SaveToBuffer(dict.Get(pp::Var(kJSToken)).AsString());
+    } else {
+      SaveToFile(dict.Get(pp::Var(kJSToken)).AsString());
+    }
   } else if (type == kJSRotateClockwiseType) {
     RotateClockwise();
   } else if (type == kJSRotateCounterclockwiseType) {
@@ -1473,37 +1480,58 @@ void OutOfProcessInstance::GetDocumentPassword(
   PostMessage(message);
 }
 
-void OutOfProcessInstance::Save(const std::string& token) {
-  engine_->KillFormFocus();
+bool OutOfProcessInstance::ShouldSaveEdits() const {
+  return edit_mode_ &&
+         base::FeatureList::IsEnabled(features::kSaveEditedPDFForm);
+}
 
-  if (!base::FeatureList::IsEnabled(features::kSaveEditedPDFForm) ||
-      !edit_mode_) {
-    ConsumeSaveToken(token);
-    pp::PDF::SaveAs(this);
-    return;
-  }
+void OutOfProcessInstance::SaveToBuffer(const std::string& token) {
+  engine_->KillFormFocus();
 
   GURL url(url_);
   std::string file_name = url.ExtractFileName();
   file_name = net::UnescapeURLComponent(file_name, net::UnescapeRule::SPACES);
-  std::vector<uint8_t> data = engine_->GetSaveData();
-
-  if (data.size() == 0u || data.size() > kMaximumSavedFileSize) {
-    // TODO(thestig): Add feedback to the user that a failure occurred.
-    ConsumeSaveToken(token);
-    return;
-  }
 
   pp::VarDictionary message;
   message.Set(kType, kJSSaveDataType);
   message.Set(kJSToken, pp::Var(token));
   message.Set(kJSFileName, pp::Var(file_name));
-  pp::VarArrayBuffer buffer(data.size());
-  std::copy(data.begin(), data.end(), reinterpret_cast<char*>(buffer.Map()));
-  message.Set(kJSDataToSave, buffer);
+  // This will be overwritten if the save is successful.
+  message.Set(kJSDataToSave, pp::Var(pp::Var::Null()));
+
+  if (ShouldSaveEdits()) {
+    std::vector<uint8_t> data = engine_->GetSaveData();
+    if (data.size() > 0 && data.size() <= kMaximumSavedFileSize) {
+      pp::VarArrayBuffer buffer(data.size());
+      std::copy(data.begin(), data.end(),
+                reinterpret_cast<char*>(buffer.Map()));
+      message.Set(kJSDataToSave, buffer);
+    }
+  } else {
+    DCHECK(base::FeatureList::IsEnabled(features::kPDFAnnotations));
+    uint32_t length = engine_->GetLoadedByteSize();
+    if (length > 0 && length <= kMaximumSavedFileSize) {
+      pp::VarArrayBuffer buffer(length);
+      if (engine_->ReadLoadedBytes(length, buffer.Map())) {
+        message.Set(kJSDataToSave, buffer);
+      }
+    }
+  }
+
   PostMessage(message);
 }
 
+void OutOfProcessInstance::SaveToFile(const std::string& token) {
+  if (!ShouldSaveEdits()) {
+    engine_->KillFormFocus();
+    ConsumeSaveToken(token);
+    pp::PDF::SaveAs(this);
+    return;
+  }
+
+  SaveToBuffer(token);
+}
+
 void OutOfProcessInstance::ConsumeSaveToken(const std::string& token) {
   pp::VarDictionary message;
   message.Set(kType, kJSConsumeSaveTokenType);

pdf/out_of_process_instance.h

@@ -186,7 +186,9 @@ class OutOfProcessInstance : public pp::Instance,
   // frame's origin.
   pp::URLLoader CreateURLLoaderInternal();
 
-  void Save(const std::string& token);
+  bool ShouldSaveEdits() const;
+  void SaveToFile(const std::string& token);
+  void SaveToBuffer(const std::string& token);
   void ConsumeSaveToken(const std::string& token);
 
   void FormDidOpen(int32_t result);

pdf/pdf_engine.h

@@ -412,6 +412,9 @@ class PDFEngine {
 
   // Remove focus from form widgets, consolidating the user input.
   virtual void KillFormFocus() = 0;
+
+  virtual uint32_t GetLoadedByteSize() = 0;
+  virtual bool ReadLoadedBytes(uint32_t length, void* buffer) = 0;
 };
 
 // Interface for exports that wrap the PDF engine.

pdf/pdfium/pdfium_engine.cc

@@ -535,7 +535,6 @@ gin::IsolateHolder* g_isolate_holder = nullptr;
 void SetUpV8() {
   const char* recommended = FPDF_GetRecommendedV8Flags();
   v8::V8::SetFlagsFromString(recommended, strlen(recommended));
-
   gin::IsolateHolder::Initialize(gin::IsolateHolder::kNonStrictMode,
                                  gin::IsolateHolder::kStableV8Extras,
                                  gin::ArrayBufferAllocator::SharedInstance());
@@ -1227,6 +1226,15 @@ void PDFiumEngine::KillFormFocus() {
   SetInFormTextArea(false);
 }
 
+uint32_t PDFiumEngine::GetLoadedByteSize() {
+  return doc_loader_->GetDocumentSize();
+}
+
+bool PDFiumEngine::ReadLoadedBytes(uint32_t length, void* buffer) {
+  DCHECK_LE(length, GetLoadedByteSize());
+  return doc_loader_->GetBlock(0, length, buffer);
+}
+
 void PDFiumEngine::SetFormSelectedText(FPDF_FORMHANDLE form_handle,
                                        FPDF_PAGE page) {
   unsigned long form_sel_text_len =

pdf/pdfium/pdfium_engine.h

@@ -136,6 +136,8 @@ class PDFiumEngine : public PDFEngine,
   void OnDocumentCanceled() override;
   void CancelBrowserDownload() override;
   void KillFormFocus() override;
+  uint32_t GetLoadedByteSize() override;
+  bool ReadLoadedBytes(uint32_t length, void* buffer) override;
 
 #if defined(PDF_ENABLE_XFA)
   void UpdatePageCount();