TrimMemory strategy while offscreenPreRaster is on.

android_webview/browser/shared_renderer_state.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/shared_renderer_state.h"
 
 #include "android_webview/browser/browser_view_renderer.h"
 #include "android_webview/browser/child_frame.h"
 #include "android_webview/browser/deferred_gpu_command_service.h"
 #include "android_webview/browser/hardware_renderer.h"
@@ skipping 269 matching lines @@
 
   hardware_renderer_->DrawGL(state_restore.stencil_enabled(),
                              state_restore.framebuffer_binding_ext(),
                              draw_info);
   DeferredGpuCommandService::GetInstance()->PerformIdleWork(false);
 }
 
 void SharedRendererState::ReleaseHardwareDrawIfNeededOnUI() {
   DCHECK(ui_loop_->BelongsToCurrentThread());
   InsideHardwareReleaseReset auto_inside_hardware_release_reset(this);
+  bool offscreen_pre_raster = browser_view_renderer_->offscreen_pre_raster();
 
   browser_view_renderer_->DetachFunctorFromView();
   bool hardware_initialized = browser_view_renderer_->hardware_enabled();
   if (hardware_initialized) {
     bool draw_functor_succeeded = browser_view_renderer_->RequestDrawGL(true);
     if (!draw_functor_succeeded) {
       LOG(ERROR) << "Unable to free GL resources. Has the Window leaked?";
       // Calling release on wrong thread intentionally.
       AwDrawGLInfo info;
       info.mode = AwDrawGLInfo::kModeProcess;
       DrawGL(&info);
     }
 
-    browser_view_renderer_->ReleaseHardware();
+    if (!offscreen_pre_raster)
+      browser_view_renderer_->ReleaseHardware();

[boliu, 2015/04/15 00:31:01]

Then this is also skipping ReleaseHardware in detach, which is not right.

Probably need to expose a separate TrimMemory call, then do some refactoring in
this file

[hush (inactive), 2015/04/15 21:35:48]

Yeah. That is a problem. And it actually caused some crashes in my test. Sorry
about that! I just refactored this file.

   }
 
   GLViewRendererManager* manager = GLViewRendererManager::GetInstance();
 
   {
     base::AutoLock lock(lock_);
     if (renderer_manager_key_ != manager->NullKey()) {
       manager->Remove(renderer_manager_key_);
       renderer_manager_key_ = manager->NullKey();
     }
   }
 
-  if (hardware_initialized) {
+  if (hardware_initialized && !offscreen_pre_raster) {
     // Flush any invoke functors that's caused by ReleaseHardware.
     browser_view_renderer_->RequestDrawGL(true);
   }
 }
 
 void SharedRendererState::InitializeHardwareDrawIfNeededOnUI() {
   DCHECK(ui_loop_->BelongsToCurrentThread());
   GLViewRendererManager* manager = GLViewRendererManager::GetInstance();
 
   base::AutoLock lock(lock_);
   if (renderer_manager_key_ == manager->NullKey()) {
     renderer_manager_key_ = manager->PushBack(this);
     DeferredGpuCommandService::SetInstance();
   }
 }
 
 SharedRendererState::InsideHardwareReleaseReset::InsideHardwareReleaseReset(
     SharedRendererState* shared_renderer_state)
     : shared_renderer_state_(shared_renderer_state) {
   DCHECK(!shared_renderer_state_->IsInsideHardwareRelease());
   shared_renderer_state_->SetInsideHardwareRelease(true);
 }
 
 SharedRendererState::InsideHardwareReleaseReset::~InsideHardwareReleaseReset() {
   shared_renderer_state_->SetInsideHardwareRelease(false);
 }
 
 }  // namespace android_webview