[unseasoned-pdf] Remove DocumentLoader::Client::GetPluginInstance()

The method isn't used anywhere.

Change-Id: Iac924adb4d57f64b81b14d3386e63014f45a20fe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2949958
Commit-Queue: Daniel Hosseinian <dhoss@chromium.org>
Reviewed-by: K. Moon <kmoon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#892250}

pdf/document_loader.h

@@ -11,10 +11,6 @@
 #include <memory>
 #include <string>
 
-namespace pp {
-class Instance;
-}
-
 namespace chrome_pdf {
 
 class URLLoaderWrapper;
@@ -25,8 +21,6 @@ class DocumentLoader {
    public:
     virtual ~Client() = default;
 
-    // Gets the pp::Instance object.
-    virtual pp::Instance* GetPluginInstance() = 0;
     // Creates new URLLoader based on client settings.
     virtual std::unique_ptr<URLLoaderWrapper> CreateURLLoader() = 0;
     // Notification called when all outstanding pending requests are complete.

pdf/document_loader_impl_unittest.cc

@@ -200,7 +200,6 @@ class TestClient : public DocumentLoader::Client {
   ~TestClient() override = default;
 
   // DocumentLoader::Client overrides:
-  pp::Instance* GetPluginInstance() override { return nullptr; }
   std::unique_ptr<URLLoaderWrapper> CreateURLLoader() override {
     return std::unique_ptr<URLLoaderWrapper>(
         new TestURLLoader(partial_loader_data()));

pdf/pdfium/pdfium_engine.cc

@@ -728,10 +728,6 @@ bool PDFiumEngine::HandleDocumentLoad(std::unique_ptr<UrlLoader> loader) {
   return true;
 }
 
-pp::Instance* PDFiumEngine::GetPluginInstance() {
-  return client_->GetPluginInstance();
-}
-
 std::unique_ptr<URLLoaderWrapper> PDFiumEngine::CreateURLLoader() {
   return std::make_unique<URLLoaderWrapperImpl>(client_->CreateUrlLoader());
 }

pdf/pdfium/pdfium_engine.h

@@ -183,7 +183,6 @@ class PDFiumEngine : public PDFEngine,
                         SendThumbnailCallback send_callback) override;
 
   // DocumentLoader::Client:
-  pp::Instance* GetPluginInstance() override;
   std::unique_ptr<URLLoaderWrapper> CreateURLLoader() override;
   void OnPendingRequestComplete() override;
   void OnNewDataReceived() override;