Rebind EGL context to flush driver caches.

gpu/command_buffer/client/gles2_implementation.cc

 // Copyright (c) 2012 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.
 
 // A class to emulate GLES2 over command buffers.
 
 #include "gpu/command_buffer/client/gles2_implementation.h"
 
 #include <GLES2/gl2ext.h>
 #include <GLES2/gl2extchromium.h>
@@ skipping 309 matching lines @@
   ShallowFlushCHROMIUM();
   gpu_control_->SetSurfaceVisible(visible);
 }
 
 void GLES2Implementation::SetAggressivelyFreeResources(
     bool aggressively_free_resources) {
   TRACE_EVENT1("gpu", "GLES2Implementation::SetAggressivelyFreeResources",
                "aggressively_free_resources", aggressively_free_resources);
   aggressively_free_resources_ = aggressively_free_resources;
 
-  // ShallowFlushCHROMIUM will free resources if |aggressively_free_resources_|
-  // is false.
-  ShallowFlushCHROMIUM();
+  if (aggressively_free_resources_) {

[piman, 2015/07/13 22:48:07]

aggressively_free_resources_ && HaveRingBuffer()

That way, we only add the commands if we need to, and otherwise avoid recreating
the command buffer just to free it.

[piman, 2015/07/13 22:48:48]

aggressively_free_resources_ && helper_->HaveRingBuffer() actually, I think.

[ericrk, 2015/07/13 23:07:52]

ah, good point

+    // Ensure that we clean up as much cache memory as possible and fully flush.
+    FlushDriverCachesCHROMIUM();
+
+    // Flush will delete transfer buffer resources if
+    // |aggressively_free_resources_| is true.
+    Flush();
+  } else {
+    ShallowFlushCHROMIUM();
+  }
 }
 
 void GLES2Implementation::WaitForCmd() {
   TRACE_EVENT0("gpu", "GLES2::WaitForCmd");
   helper_->CommandBufferHelper::Finish();
 }
 
 bool GLES2Implementation::IsExtensionAvailable(const char* ext) {
   const char* extensions =
       reinterpret_cast<const char*>(GetStringHelper(GL_EXTENSIONS));
@@ skipping 5437 matching lines @@
   CheckGLError();
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/client/gles2_implementation_impl_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu