Make LayerScrollOffsetDelegate updates consistent.

android_webview/browser/browser_view_renderer.h

Index: android_webview/browser/browser_view_renderer.h
diff --git a/android_webview/browser/browser_view_renderer.h b/android_webview/browser/browser_view_renderer.h
index da82fce8ae253a37c78bfd484f6dd17108d80c87..8ee904031f77b5cf40ea4d75bd8e081b76d42a8d 100644
--- a/android_webview/browser/browser_view_renderer.h
+++ b/android_webview/browser/browser_view_renderer.h
@@ -9,6 +9,7 @@
 #include "base/android/scoped_java_ref.h"
 #include "base/callback.h"
 #include "base/cancelable_callback.h"
+#include "base/values.h"
 #include "content/public/browser/android/synchronous_compositor_client.h"
 #include "skia/ext/refptr.h"
 #include "ui/gfx/rect.h"
@@ -112,17 +113,18 @@ class BrowserViewRenderer : public content::SynchronousCompositorClient {
   virtual void DidDestroyCompositor(content::SynchronousCompositor* compositor)
       OVERRIDE;
   virtual void SetContinuousInvalidate(bool invalidate) OVERRIDE;
-  virtual void SetMaxRootLayerScrollOffset(gfx::Vector2dF new_value) OVERRIDE;
-  virtual void SetTotalRootLayerScrollOffset(gfx::Vector2dF new_value_css)
-      OVERRIDE;
+  virtual void SetTotalRootLayerScrollOffset(
+      gfx::Vector2dF new_value_dip) OVERRIDE;
   virtual void DidUpdateContent() OVERRIDE;
   virtual gfx::Vector2dF GetTotalRootLayerScrollOffset() OVERRIDE;
   virtual bool IsExternalFlingActive() const OVERRIDE;
-  virtual void SetRootLayerPageScaleFactorAndLimits(float page_scale_factor,
-                                                    float min_page_scale_factor,
-                                                    float max_page_scale_factor)
-      OVERRIDE;
-  virtual void SetRootLayerScrollableSize(gfx::SizeF scrollable_size) OVERRIDE;
+  virtual 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;
   virtual void DidOverscroll(gfx::Vector2dF accumulated_overscroll,
                              gfx::Vector2dF latest_overscroll_delta,
                              gfx::Vector2dF current_fling_velocity) OVERRIDE;
@@ -135,6 +137,8 @@ class BrowserViewRenderer : public content::SynchronousCompositorClient {
   bool DrawSWInternal(jobject java_canvas, const gfx::Rect& clip_bounds);
   bool CompositeSW(SkCanvas* canvas);
   void DidComposite(bool force_invalidate);
+  scoped_ptr<base::Value> RootLayerStateAsValue(
+      const gfx::SizeF& scrollable_size_dip);
 
   // If we call up view invalidate and OnDraw is not called before a deadline,
   // then we keep ticking the SynchronousCompositor so it can make progress.