Rewire Android WebView's compositor changed signal.

android_webview/browser/browser_view_renderer.h

 // Copyright (c) 2013 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.
 
 #ifndef ANDROID_WEBVIEW_BROWSER_BROWSER_VIEW_RENDERER_H_
 #define ANDROID_WEBVIEW_BROWSER_BROWSER_VIEW_RENDERER_H_
 
 #include <stddef.h>
 
 #include <map>
 #include <set>
 
 #include "android_webview/browser/compositor_frame_producer.h"
+#include "android_webview/browser/compositor_id.h"
 #include "android_webview/browser/parent_compositor_draw_constraints.h"
 #include "base/callback.h"
 #include "base/cancelable_callback.h"
 #include "base/macros.h"
 #include "base/trace_event/trace_event.h"
 #include "content/public/browser/android/synchronous_compositor.h"
 #include "content/public/browser/android/synchronous_compositor_client.h"
+#include "content/public/browser/web_contents_observer.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size_f.h"
 #include "ui/gfx/geometry/vector2d_f.h"
 
 class SkCanvas;
 class SkPicture;
 
 namespace content {
+class RenderViewHost;
 class WebContents;
 }
 
 namespace android_webview {
 
 class BrowserViewRendererClient;
 class ChildFrame;
 class CompositorFrameConsumer;
 
 // Interface for all the WebView-specific content rendering operations.
 // Provides software and hardware rendering and the Capture Picture API.
 class BrowserViewRenderer : public content::SynchronousCompositorClient,
+                            public content::WebContentsObserver,
                             public CompositorFrameProducer {
  public:
   static void CalculateTileMemoryPolicy();
   static BrowserViewRenderer* FromWebContents(
       content::WebContents* web_contents);
 
   BrowserViewRenderer(
+      content::WebContents* web_contents,
       BrowserViewRendererClient* client,
       const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner);
 
   ~BrowserViewRenderer() override;
 
   void RegisterWithWebContents(content::WebContents* web_contents);
 
   // The BrowserViewRenderer client is responsible for ensuring that
   // the current compositor frame consumer has been set correctly via
   // this method.  The consumer is added to the set of registered
@@ skipping 42 matching lines @@
   // Android views hierarchy gluing.
   bool IsVisible() const;
   gfx::Rect GetScreenRect() const;
   bool attached_to_window() const { return attached_to_window_; }
   gfx::Size size() const { return size_; }
 
   bool IsClientVisible() const;
   void TrimMemory();
 
   // SynchronousCompositorClient overrides.
-  void DidInitializeCompositor(
-      content::SynchronousCompositor* compositor) override;
-  void DidDestroyCompositor(
-      content::SynchronousCompositor* compositor) override;
-  void DidBecomeCurrent(content::SynchronousCompositor* compositor) override;
+  void DidInitializeCompositor(content::SynchronousCompositor* compositor,
+                               int process_id,
+                               int routing_id) override;
+  void DidDestroyCompositor(content::SynchronousCompositor* compositor,
+                            int process_id,
+                            int routing_id) override;
   void PostInvalidate() override;
   void DidUpdateContent() override;
   void UpdateRootLayerState(const gfx::Vector2dF& total_scroll_offset_dip,
                             const gfx::Vector2dF& max_scroll_offset_dip,
                             const gfx::SizeF& scrollable_size_dip,
                             float page_scale_factor,
                             float min_page_scale_factor,
                             float max_page_scale_factor) override;
   void DidOverscroll(const gfx::Vector2dF& accumulated_overscroll,
                      const gfx::Vector2dF& latest_overscroll_delta,
                      const gfx::Vector2dF& current_fling_velocity) override;
 
+  // content::WebContentsObserver overrides
+  void RenderViewHostChanged(content::RenderViewHost* old_host,
+                             content::RenderViewHost* new_host) override;
+
   // CompositorFrameProducer overrides
   void OnParentDrawConstraintsUpdated(
       CompositorFrameConsumer* compositor_frame_consumer) override;
   void RemoveCompositorFrameConsumer(
       CompositorFrameConsumer* compositor_frame_consumer) override;
 
  private:
   void SetTotalRootLayerScrollOffset(const gfx::Vector2dF& new_value_dip);
   bool CanOnDraw();
   void UpdateCompositorIsActive();
@@ skipping 15 matching lines @@
   // For debug tracing or logging. Return the string representation of this
   // view renderer's state.
   std::string ToString() const;
 
   BrowserViewRendererClient* const client_;
   const scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
   CompositorFrameConsumer* current_compositor_frame_consumer_;
   std::set<CompositorFrameConsumer*> compositor_frame_consumers_;
 
   // The current compositor that's owned by the current RVH.
+  // When compositor_ != nullptr, compositor_id_ is the id of compositor_.
+  // When compositor_ == nullptr, compositor_id_ is the id of the future
+  // compositor.
   content::SynchronousCompositor* compositor_;
+  CompositorID compositor_id_;
   // A map from compositor's per-WebView unique ID to the compositor's raw
   // pointer. A raw pointer here is fine because the entry will be erased when
   // a compositor is destroyed.
-  std::map<size_t, content::SynchronousCompositor*> compositor_map_;
+  std::map<CompositorID, content::SynchronousCompositor*> compositor_map_;
 
   bool is_paused_;
   bool view_visible_;
   bool window_visible_;  // Only applicable if |attached_to_window_| is true.
   bool attached_to_window_;
   bool hardware_enabled_;
   float dip_scale_;
   float page_scale_factor_;
   float min_page_scale_factor_;
   float max_page_scale_factor_;
@@ skipping 16 matching lines @@
   // Max scroll offset in CSS pixels.
   // TODO(miletus): Make max_scroll_offset_dip_ a gfx::ScrollOffset.
   gfx::Vector2dF max_scroll_offset_dip_;
 
   // Used to prevent rounding errors from accumulating enough to generate
   // visible skew (especially noticeable when scrolling up and down in the same
   // spot over a period of time).
   // TODO(miletus): Make overscroll_rounding_error_ a gfx::ScrollOffset.
   gfx::Vector2dF overscroll_rounding_error_;
 
-  uint32_t next_compositor_id_;
-
   ParentCompositorDrawConstraints external_draw_constraints_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserViewRenderer);
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_BROWSER_VIEW_RENDERER_H_