Resize only the virtual viewport when the OSK triggers a resize.

content/browser/renderer_host/render_widget_host_view_android.h

 // Copyright (c) 2012 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 CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_ANDROID_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_ANDROID_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 87 matching lines @@
   gfx::NativeViewId GetNativeViewId() const override;
   gfx::NativeViewAccessible GetNativeViewAccessible() override;
   void MovePluginWindows(const std::vector<WebPluginGeometry>& moves) override;
   void Focus() override;
   bool HasFocus() const override;
   bool IsSurfaceAvailableForCopy() const override;
   void Show() override;
   void Hide() override;
   bool IsShowing() override;
   gfx::Rect GetViewBounds() const override;
+  gfx::Size GetVisibleViewportSize() const override;
   gfx::Size GetPhysicalBackingSize() const override;
   bool DoTopControlsShrinkBlinkSize() const override;
   float GetTopControlsHeight() const override;
   void UpdateCursor(const WebCursor& cursor) override;
   void SetIsLoading(bool is_loading) override;
   void TextInputStateChanged(
       const ViewHostMsg_TextInputState_Params& params) override;
   void ImeCancelComposition() override;
   void ImeCompositionRangeChanged(
       const gfx::Range& range,
@@ skipping 306 matching lines @@
   gfx::Vector2dF last_scroll_offset_;
 
   base::WeakPtrFactory<RenderWidgetHostViewAndroid> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewAndroid);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_ANDROID_H_