[android] Resize the android_webview if it's 0x0 initially.

android_webview/browser/renderer_host/view_renderer_host.cc

 // 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.
 
 #include "android_webview/browser/renderer_host/view_renderer_host.h"
 
 #include "android_webview/browser/scoped_allow_wait_for_legacy_web_view_api.h"
 #include "android_webview/common/aw_switches.h"
 #include "android_webview/common/render_view_messages.h"
 #include "android_webview/common/renderer_picture_map.h"
 #include "base/command_line.h"
 #include "content/public/browser/android/content_view_core.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCompositorInputHandler.h"
 
 namespace android_webview {
 
 ViewRendererHost::ViewRendererHost(content::WebContents* contents,
                                    Client* client)
     : content::WebContentsObserver(contents),
       client_(client) {
+  DCHECK(client);
 }
 
 ViewRendererHost::~ViewRendererHost() {
 }
 
 void ViewRendererHost::CapturePictureSync() {
   if (!IsRenderViewReady())
     return;
 
   ScopedAllowWaitForLegacyWebViewApi wait;
   Send(new AwViewMsg_CapturePictureSync(web_contents()->GetRoutingID()));
 }
 
 void ViewRendererHost::EnableCapturePictureCallback(bool enabled) {
   Send(new AwViewMsg_EnableCapturePictureCallback(
       web_contents()->GetRoutingID(), enabled));
 }
 
 void ViewRendererHost::OnPictureUpdated() {
-  if (client_) {
-    client_->OnPictureUpdated(web_contents()->GetRenderProcessHost()->GetID(),
-        routing_id());
-  }
+  client_->OnPictureUpdated(web_contents()->GetRenderProcessHost()->GetID(),
+                            routing_id());
 }
 
 void ViewRendererHost::OnDidActivateAcceleratedCompositing(
     int input_handler_id) {
 
   if (!CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kMergeUIAndRendererCompositorThreads)) {
     return;
   }
 
   // This call is only meaningful and thread-safe when the UI and renderer
   // compositor share the same thread.  Any other case will likely yield
   // terrible, terrible damage.
   WebKit::WebCompositorInputHandler* input_handler =
       WebKit::WebCompositorInputHandler::fromIdentifier(input_handler_id);
   if (!input_handler)
     return;
 
   content::ContentViewCore* content_view_core
       = content::ContentViewCore::FromWebContents(web_contents());
   if (content_view_core)
     content_view_core->SetInputHandler(input_handler);
 }
 
+void ViewRendererHost::OnPageScaleFactorChanged(float page_scale_factor) {
+  client_->OnPageScaleFactorChanged(
+      web_contents()->GetRenderProcessHost()->GetID(),
+      routing_id(),
+      page_scale_factor);
+}
+
 void ViewRendererHost::RenderViewGone(base::TerminationStatus status) {
   DCHECK(CalledOnValidThread());
   RendererPictureMap::GetInstance()->ClearRendererPicture(
       web_contents()->GetRoutingID());
 }
 
 bool ViewRendererHost::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ViewRendererHost, message)
     IPC_MESSAGE_HANDLER(AwViewHostMsg_PictureUpdated,
                         OnPictureUpdated)
     IPC_MESSAGE_HANDLER(AwViewHostMsg_DidActivateAcceleratedCompositing,
                         OnDidActivateAcceleratedCompositing)
+    IPC_MESSAGE_HANDLER(AwViewHostMsg_PageScaleFactorChanged,
+                        OnPageScaleFactorChanged)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   return handled ? true : WebContentsObserver::OnMessageReceived(message);
 }
 
 bool ViewRendererHost::IsRenderViewReady() const {
   return web_contents()->GetRenderProcessHost()->HasConnection() &&
       web_contents()->GetRenderViewHost() &&
       web_contents()->GetRenderViewHost()->IsRenderViewLive();
 }
 
 }  // namespace android_webview