aw: Skip hardware onDraw when visible rect is empty

android_webview/browser/browser_view_renderer.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 "android_webview/browser/browser_view_renderer.h"
 
 #include "android_webview/browser/browser_view_renderer_client.h"
 #include "android_webview/browser/shared_renderer_state.h"
 #include "android_webview/common/aw_switches.h"
 #include "android_webview/public/browser/draw_gl.h"
@@ skipping 246 matching lines @@
   }
 
   // Perform a software draw
   return OnDrawSoftware(java_canvas);
 }
 
 bool BrowserViewRenderer::OnDrawHardware(jobject java_canvas) {
   if (!compositor_)
     return false;
 
+  if (last_on_draw_global_visible_rect_.IsEmpty())
+    return client_->RequestDrawGL(java_canvas, false);
+
   if (!hardware_enabled_) {
     hardware_enabled_ = compositor_->InitializeHwDraw();
     if (hardware_enabled_) {
       tile_manager_key_ = GlobalTileManager::GetInstance()->PushBack(this);
       gpu::GLInProcessContext* share_context = compositor_->GetShareContext();
       DCHECK(share_context);
       shared_renderer_state_->SetSharedContext(share_context);
     }
   }
   if (!hardware_enabled_)
@@ skipping 538 matching lines @@
     base::StringAppendF(&str,
                         "surface width height: [%d %d] ",
                         draw_info->width,
                         draw_info->height);
     base::StringAppendF(&str, "is_layer: %d ", draw_info->is_layer);
   }
   return str;
 }
 
 }  // namespace android_webview