Hookup android_webview scroll offset delegation to Java side.

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 e24b25ca44a0987fc1d5a59dc0a216932fbce253..bea797c140b6fb0f8d158ae414240831604de32a 100644
--- a/android_webview/browser/browser_view_renderer.h
+++ b/android_webview/browser/browser_view_renderer.h
@@ -8,6 +8,7 @@
 #include "base/android/scoped_java_ref.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
+#include "ui/gfx/vector2d_f.h"
 
 struct AwDrawGLInfo;
 struct AwDrawSWFunctionTable;
@@ -16,10 +17,6 @@ namespace content {
 class ContentViewCore;
 }
 
-namespace gfx {
-class Rect;
-}
-
 namespace android_webview {
 
 // Interface for all the WebView-specific content rendering operations.
@@ -43,6 +40,9 @@ class BrowserViewRenderer {
     // Called to get view's absolute location on the screen.
     virtual gfx::Point GetLocationOnScreen() = 0;
 
+    // Try to set the view's scroll offset to |new_value_css|.
+    virtual void ScrollContainerViewTo(gfx::Vector2dF new_value_css) = 0;
+
    protected:
     virtual ~Client() {}
   };
@@ -91,7 +91,7 @@ class BrowserViewRenderer {
   // scroll offset. |clip| is the canvas's clip bounds.
   virtual bool OnDraw(jobject java_canvas,
                       bool is_hardware_canvas,
-                      const gfx::Point& scroll,
+                      const gfx::Vector2d& scroll_pix,

[joth, 2013/06/18 03:19:50]

is _pix a standard convention? If not, it doesn't seem to add much (as we have
numerous types of pixel) - the fact it's non-float suggests me it's physical px.

[mkosiba (inactive), 2013/06/18 18:09:25]

it seems to be the convention used in RenderCorrdinates. Now I'm thinking it may
be sufficient to call out the stuff that's in CSS pixels, and assume everything
else in the renderer is in physical pixels.

                       const gfx::Rect& clip) = 0;
   // Called in response to a prior Client::RequestDrawGL() call. See
   // AwDrawGLInfo documentation for more details of the contract.
@@ -107,6 +107,10 @@ class BrowserViewRenderer {
   virtual void OnAttachedToWindow(int width, int height) = 0;
   virtual void OnDetachedFromWindow() = 0;
 
+  // Set the root layer scroll offset to |new_value|. |new_value| is in
+  // physical pixels.

[joth, 2013/06/18 03:19:50]

physical pixels? these are normally scalar, not floats. (AIUI)

[mkosiba (inactive), 2013/06/18 18:09:25]

Done.

+  virtual void ScrollTo(gfx::Vector2dF new_value) = 0;
+
   // Android views hierarchy gluing.
   virtual bool IsAttachedToWindow() = 0;
   virtual bool IsViewVisible() = 0;