Add WebContentObserver::SafeAreaConstraintChanged

Add the method to be integrated once crrev.com/c/6107457 lands.

Bug: 385221500
Change-Id: I879c765e9835bda414be2fbb3b8e0f6ed0c50e7e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6115531
Reviewed-by: Charles Hager <clhager@google.com>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Wenyu Fu <wenyufu@chromium.org>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1400528}

chrome/android/java/src/org/chromium/chrome/browser/tab/TabWebContentsObserver.java

@@ -359,13 +359,19 @@ public class TabWebContentsObserver extends TabWebContentsUserData {
         @Override
         public void viewportFitChanged(@WebContentsObserver.ViewportFitType int value) {
             DisplayCutoutTabHelper.from(mTab).setViewportFit(value);
-            // TODO(wenyufu): Create a setSafeAreaConstraint method.
             if (ChromeFeatureList.sEdgeToEdgeSafeAreaConstraint.isEnabled()) {
                 DisplayCutoutTabHelper.from(mTab)
                         .setSafeAreaConstraint(value == ViewportFit.CONTAIN);
             }
         }
 
+        @Override
+        public void safeAreaConstraintChanged(boolean hasConstraint) {
+            if (ChromeFeatureList.sEdgeToEdgeSafeAreaConstraint.isEnabled()) {
+                DisplayCutoutTabHelper.from(mTab).setSafeAreaConstraint(hasConstraint);
+            }
+        }
+
         @Override
         public void virtualKeyboardModeChanged(@VirtualKeyboardMode.EnumType int mode) {
             RewindableIterator<TabObserver> observers = mTab.getTabObservers();

content/browser/android/web_contents_observer_proxy.cc

@@ -318,6 +318,12 @@ void WebContentsObserverProxy::ViewportFitChanged(
       env, java_observer_, as_jint(static_cast<int>(value)));
 }
 
+void WebContentsObserverProxy::SafeAreaConstraintChanged(bool has_constraint) {
+  JNIEnv* env = AttachCurrentThread();
+  Java_WebContentsObserverProxy_safeAreaConstraintChanged(env, java_observer_,
+                                                          has_constraint);
+}
+
 void WebContentsObserverProxy::VirtualKeyboardModeChanged(
     ui::mojom::VirtualKeyboardMode mode) {
   JNIEnv* env = AttachCurrentThread();

content/browser/android/web_contents_observer_proxy.h

@@ -77,6 +77,7 @@ class WebContentsObserverProxy : public WebContentsObserver {
                                      bool will_cause_resize) override;
   bool SetToBaseURLForDataURLIfNeeded(GURL* url);
   void ViewportFitChanged(blink::mojom::ViewportFit value) override;
+  void SafeAreaConstraintChanged(bool has_constriant) override;
   void VirtualKeyboardModeChanged(ui::mojom::VirtualKeyboardMode mode) override;
   void OnWebContentsFocused(RenderWidgetHost*) override;
   void OnWebContentsLostFocus(RenderWidgetHost*) override;

content/browser/display_cutout/safe_area_insets_host.h

@@ -70,6 +70,10 @@ class CONTENT_EXPORT SafeAreaInsetsHost
   // Protected and virtual for testing only.
   virtual void SendSafeAreaToFrame(RenderFrameHost* rfh, gfx::Insets insets);
 
+  // Notified that the complex safe-area-inset constraint state changed.
+  virtual void ComplexSafeAreaConstraintChangedForFrame(RenderFrameHost* rfh,
+                                                        bool has_constraint) {}
+
   // Weak pointer to the owning `WebContentsImpl` instance.
   raw_ptr<WebContentsImpl> web_contents_impl_;
 

content/browser/display_cutout/safe_area_insets_host_impl.cc

@@ -103,6 +103,13 @@ void SafeAreaInsetsHostImpl::ViewportFitChangedForFrame(
   }
 }
 
+void SafeAreaInsetsHostImpl::ComplexSafeAreaConstraintChangedForFrame(
+    RenderFrameHost* rfh,
+    bool has_constraint) {
+  DCHECK(rfh);
+  web_contents_impl_->NotifySafeAreaConstraintChanged(has_constraint);
+}
+
 void SafeAreaInsetsHostImpl::MaybeActiveRenderFrameHostChanged() {
   base::WeakPtr<RenderFrameHostImpl> new_active_rfh =
       fullscreen_rfh_ ? fullscreen_rfh_ : current_rfh_;

content/browser/display_cutout/safe_area_insets_host_impl.h

@@ -59,6 +59,8 @@ class CONTENT_EXPORT SafeAreaInsetsHostImpl : public SafeAreaInsetsHost {
   // SafeAreaInsetsHost override.
   void ViewportFitChangedForFrame(RenderFrameHost* rfh,
                                   blink::mojom::ViewportFit value) override;
+  void ComplexSafeAreaConstraintChangedForFrame(RenderFrameHost* rfh,
+                                                bool has_constraint) override;
 
   // Get the stored viewport fit value for a frame or kAuto if there is no
   // stored value.

content/browser/web_contents/web_contents_impl.cc

@@ -2213,6 +2213,14 @@ void WebContentsImpl::NotifyViewportFitChanged(
   observers_.NotifyObservers(&WebContentsObserver::ViewportFitChanged, value);
 }
 
+void WebContentsImpl::NotifySafeAreaConstraintChanged(bool has_constraint) {
+  OPTIONAL_TRACE_EVENT1("content",
+                        "WebContentsImpl::NotifySafeAreaConstraintChanged",
+                        "has_constraint", has_constraint);
+  observers_.NotifyObservers(&WebContentsObserver::SafeAreaConstraintChanged,
+                             has_constraint);
+}
+
 FindRequestManager* WebContentsImpl::GetFindRequestManagerForTesting() {
   return GetOrCreateFindRequestManager();
 }

content/browser/web_contents/web_contents_impl.h

@@ -1437,8 +1437,11 @@ class CONTENT_EXPORT WebContentsImpl
 #endif
 
   // Notify observers that the viewport fit value changed. This is called by
-  // |DisplayCutoutHostImpl|.
+  // |SafeAreaInsetsHost|.
   void NotifyViewportFitChanged(blink::mojom::ViewportFit value);
+  // Notify observers that safe area constraint has changed. This is called by
+  // |SafeAreaInsetsHost|.
+  void NotifySafeAreaConstraintChanged(bool has_constraint);
 
   // Returns the current FindRequestManager associated with the WebContents;
   // this won't create one if none exists.

content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsObserverProxy.java

@@ -438,6 +438,16 @@ class WebContentsObserverProxy extends WebContentsObserver {
         finishObserverCall();
     }
 
+    @Override
+    @CalledByNative
+    public void safeAreaConstraintChanged(boolean hasConstraint) {
+        handleObserverCall();
+        for (WebContentsObserver mObserver : mObservers) {
+            mObserver.safeAreaConstraintChanged(hasConstraint);
+        }
+        finishObserverCall();
+    }
+
     @Override
     @CalledByNative
     public void virtualKeyboardModeChanged(@VirtualKeyboardMode.EnumType int mode) {

content/public/android/java/src/org/chromium/content_public/browser/WebContentsObserver.java

@@ -204,12 +204,21 @@ public abstract class WebContentsObserver {
 
     /**
      * Called when the viewport fit of the Web Contents changes.
+     *
      * @param value the new viewport fit value.
      */
     public void viewportFitChanged(@ViewportFitType int value) {}
 
+    /**
+     * Called when the safe area constraint of the Web Contents changes.
+     *
+     * @param hasConstraint Whether there are safe area constraint.
+     */
+    public void safeAreaConstraintChanged(boolean hasConstraint) {}
+
     /**
      * Called when the virtual keyboard mode of the Web Contents changes.
+     *
      * @param mode the new virtual keyboard mode.
      */
     public void virtualKeyboardModeChanged(@VirtualKeyboardMode.EnumType int mode) {}

content/public/browser/web_contents_observer.h

@@ -681,6 +681,9 @@ class CONTENT_EXPORT WebContentsObserver : public base::CheckedObserver {
   // This method is called when the viewport fit of a WebContents changes.
   virtual void ViewportFitChanged(blink::mojom::ViewportFit value) {}
 
+  // This method is called when the safe area constraint changed.
+  virtual void SafeAreaConstraintChanged(bool has_constraint) {}
+
   // This method is called when the virtual keyboard mode of a WebContents
   // changes. This can happen as a result of the
   // `navigator.virtualKeyboard.overlaysContent` API or the virtual-keyboard key