aw: Skip hardware onDraw when visible rect is empty

android_webview/browser/hardware_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/hardware_renderer.h"
 
 #include "android_webview/browser/aw_gl_surface.h"
 #include "android_webview/browser/deferred_gpu_command_service.h"
 #include "android_webview/browser/parent_output_surface.h"
 #include "android_webview/browser/shared_renderer_state.h"
@@ skipping 121 matching lines @@
   // This is called after OutputSurface is created, but before the impl frame
   // starts. We set the draw constraints here.
   DCHECK(output_surface_);
   DCHECK(viewport_clip_valid_for_dcheck_);
   output_surface_->SetExternalStencilTest(stencil_enabled_);
   output_surface_->SetDrawConstraints(viewport_, clip_);
 }
 
 void HardwareRenderer::CommitFrame() {
   scoped_ptr<DrawGLInput> input = shared_renderer_state_->PassDrawGLInput();
-  if (!input.get()) {
-    DLOG(WARNING) << "No frame to commit";
+  // Happens with empty global visible rect.
+  if (!input.get())
     return;
-  }
 
   DCHECK(!input->frame.gl_frame_data);
   DCHECK(!input->frame.software_frame_data);
 
   // DelegatedRendererLayerImpl applies the inverse device_scale_factor of the
   // renderer frame, assuming that the browser compositor will scale
   // it back up to device scale.  But on Android we put our browser layers in
   // physical pixels and set our browser CC device_scale_factor to 1, so this
   // suppresses the transform.
   input->frame.delegated_frame_data->device_scale_factor = 1.0f;
@@ skipping 29 matching lines @@
   TRACE_EVENT0("android_webview", "HardwareRenderer::DrawGL");
 
   // We need to watch if the current Android context has changed and enforce
   // a clean-up in the compositor.
   EGLContext current_context = eglGetCurrentContext();
   if (!current_context) {
     DLOG(ERROR) << "DrawGL called without EGLContext";
     return;
   }
 
-  if (!delegated_layer_.get()) {
-    DLOG(ERROR) << "No frame committed";
-    return;
-  }
-
   // TODO(boliu): Handle context loss.
   if (last_egl_context_ != current_context)
     DLOG(WARNING) << "EGLContextChanged";
 
   gfx::Transform transform(gfx::Transform::kSkipInitialization);
   transform.matrix().setColMajorf(draw_info->transform);
   transform.Translate(scroll_offset_.x(), scroll_offset_.y());
 
   // Need to post the new transform matrix back to child compositor
   // because there is no onDraw during a Render Thread animation, and child
   // compositor might not have the tiles rasterized as the animation goes on.
   ParentCompositorDrawConstraints draw_constraints(
       draw_info->is_layer, transform, gfx::Rect(viewport_));
   if (!draw_constraints_.Equals(draw_constraints)) {
     draw_constraints_ = draw_constraints;
     shared_renderer_state_->PostExternalDrawConstraintsToChildCompositor(
         draw_constraints);
   }
 
+  if (!delegated_layer_.get())
+    return;
+
   viewport_.SetSize(draw_info->width, draw_info->height);
   layer_tree_host_->SetViewportSize(viewport_);
   clip_.SetRect(draw_info->clip_left,
                 draw_info->clip_top,
                 draw_info->clip_right - draw_info->clip_left,
                 draw_info->clip_bottom - draw_info->clip_top);
   stencil_enabled_ = stencil_enabled;
 
   delegated_layer_->SetTransform(transform);
 
@@ skipping 22 matching lines @@
 }
 
 void HardwareRenderer::UnusedResourcesAreAvailable() {
   cc::ReturnedResourceArray returned_resources;
   resource_collection_->TakeUnusedResourcesForChildCompositor(
       &returned_resources);
   shared_renderer_state_->InsertReturnedResources(returned_resources);
 }
 
 }  // namespace android_webview