Implement overscroll support for the virtual keyboard.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index ad374246f96ac5d750fb9703868bb584f8262ff5..7dcda33f215a105ede5437a74f0f2b5750f550c8 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -875,6 +875,33 @@ void RenderWidgetHostViewAura::SetBackground(const SkBitmap& background) {
   window_->layer()->SetFillsBoundsOpaquely(background.isOpaque());
 }
 
+gfx::SizeF RenderWidgetHostViewAura::GetVisibleViewportSize() const {
+  gfx::Rect window_bounds = window_->GetBoundsInScreen();
+  aura::Window* root_window = window_->GetRootWindow();
+  if (root_window) {
+    gfx::Rect root_window_bounds = root_window->GetBoundsInScreen();
+    gfx::Rect available_bounds = gfx::Rect(
+        root_window_bounds.x() + root_window_insets_.left(),
+        root_window_bounds.y() + root_window_insets_.top(),
+        root_window_bounds.width() - root_window_insets_.left() -
+            root_window_insets_.right(),

[sky, 2014/04/24 15:55:09]

The insets should be relative to window_, not the root.

[kevers, 2014/04/24 18:38:33]

Done.  Added TODOs to keyboard controller to address issues that need to be
fixed if a window is moved while the keyboard is visible.

+        root_window_bounds.height() - root_window_insets_.top() -
+            root_window_insets_.bottom());
+    gfx::Rect intersect = gfx::IntersectRects(window_bounds, available_bounds);
+    int overlap = intersect.height();
+    if (overlap > 0 && overlap < window_bounds.height())
+      return gfx::SizeF(intersect.width(), intersect.height());
+  }
+  return gfx::SizeF(GetViewBounds().width(), GetViewBounds().height());
+}
+
+void RenderWidgetHostViewAura::SetInsets(const gfx::Insets& insets) {
+  if (insets != root_window_insets_) {
+    root_window_insets_ = insets;
+    host_->WasResized();
+  }
+}
+
 void RenderWidgetHostViewAura::UpdateCursor(const WebCursor& cursor) {
   current_cursor_ = cursor;
   const gfx::Display display = gfx::Screen::GetScreenFor(window_)->