Remove RWHV::SetBounds() from the public API, and make comments clearer.

chrome/browser/ui/web_contents_sizer.cc

 // Copyright 2014 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 "chrome/browser/ui/web_contents_sizer.h"
 
+#include "base/logging.h"
 #include "build/build_config.h"
 #include "content/public/browser/web_contents.h"
 
 #if defined(USE_AURA)
 #include "ui/aura/window.h"
 #elif defined(OS_ANDROID)
 #include "content/public/browser/render_widget_host_view.h"
 #endif
+#include "content/public/browser/web_contents.h"
 
 void ResizeWebContents(content::WebContents* web_contents,
                        const gfx::Rect& new_bounds) {
+  DCHECK(web_contents);
 #if defined(USE_AURA)
+  // TODO(miu): This direct manipulation of the aura::Window should be removed.
+  // Currently, this is requried because some callers of ResizeWebContents() do
+  // so just after a new WebContents is created, but before the
+  // RenderWidgetHostView for the main frame has not been created yet.
+  // http://crbug.com/693953
   aura::Window* window = web_contents->GetNativeView();
   window->SetBounds(gfx::Rect(window->bounds().origin(), new_bounds.size()));
 #elif defined(OS_ANDROID)
-  content::RenderWidgetHostView* view = web_contents->GetRenderWidgetHostView();
-  if (view)
-    view->SetBounds(new_bounds);
+  if (auto* view = web_contents->GetRenderWidgetHostView())
+    view->SetSize(new_bounds.size());
 #endif
 }