Use a singleton 1x1 offscreen surface for all TextureImageTransportSurface instances.

This is to reduce the number of dummy offscreen surfaces created for the purpose of
making TextureImageTransportSurface current.

BUG=NONE
TEST=manually on daisy; verified that the dummy surface only gets allocated when first needed and
destroyed when the last instance of TextureImageTrasnportSurface is destroyed.


Review URL: https://chromiumcodereview.appspot.com/10984004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@158512 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 22 insertions, 8 deletions

diff --git a/content/common/gpu/gpu_channel_manager.cc b/content/common/gpu/gpu_channel_manager.cc
index be60a19..1da6aec 100644
--- a/content/common/gpu/gpu_channel_manager.cc
+++ b/content/common/gpu/gpu_channel_manager.cc
@@ -38,6 +38,10 @@ GpuChannelManager::GpuChannelManager(ChildThread* gpu_child_thread,
 
 GpuChannelManager::~GpuChannelManager() {
   gpu_channels_.clear();
+  if (default_offscreen_surface_.get()) {
+    default_offscreen_surface_->Destroy();
+    default_offscreen_surface_ = NULL;
+  }
 }
 
 gpu::gles2::ProgramCache* GpuChannelManager::program_cache() {
@@ -175,3 +179,11 @@ void GpuChannelManager::LoseAllContexts() {
 void GpuChannelManager::OnLoseAllContexts() {
   gpu_channels_.clear();
 }
+
+gfx::GLSurface* GpuChannelManager::GetDefaultOffscreenSurface() {
+  if (!default_offscreen_surface_.get()) {
+    default_offscreen_surface_ = gfx::GLSurface::CreateOffscreenGLSurface(
+        false, gfx::Size(1, 1));
+  }
+  return default_offscreen_surface_.get();
+}
diff --git a/content/common/gpu/gpu_channel_manager.h b/content/common/gpu/gpu_channel_manager.h
index 3e4af65..b256a56 100644
--- a/content/common/gpu/gpu_channel_manager.h
+++ b/content/common/gpu/gpu_channel_manager.h
@@ -17,6 +17,7 @@
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sender.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/gl/gl_surface.h"
 
 namespace base {
 class WaitableEvent;
@@ -92,6 +93,8 @@ class GpuChannelManager : public IPC::Listener,
 
   SyncPointManager* sync_point_manager() { return sync_point_manager_; }
 
+  gfx::GLSurface* GetDefaultOffscreenSurface();
+
  private:
   // Message handlers.
   void OnEstablishChannel(int client_id, bool share_context);
@@ -123,6 +126,7 @@ class GpuChannelManager : public IPC::Listener,
   GpuWatchdog* watchdog_;
   scoped_refptr<SyncPointManager> sync_point_manager_;
   scoped_ptr<gpu::gles2::ProgramCache> program_cache_;
+  scoped_refptr<gfx::GLSurface> default_offscreen_surface_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuChannelManager);
 };
diff --git a/content/common/gpu/gpu_command_buffer_stub.cc b/content/common/gpu/gpu_command_buffer_stub.cc
index 6661447..967f153 100644
--- a/content/common/gpu/gpu_command_buffer_stub.cc
+++ b/content/common/gpu/gpu_command_buffer_stub.cc
@@ -375,8 +375,8 @@ void GpuCommandBufferStub::OnInitialize(
         this,
         handle_);
   } else {
-    surface_ = gfx::GLSurface::CreateOffscreenGLSurface(software_,
-                                                        gfx::Size(1, 1));
+    GpuChannelManager* manager = channel_->gpu_channel_manager();
+    surface_ = manager->GetDefaultOffscreenSurface();
   }
 
   if (!surface_.get()) {
diff --git a/content/common/gpu/texture_image_transport_surface.cc b/content/common/gpu/texture_image_transport_surface.cc
index c6d28e0..86f5ebc 100644
--- a/content/common/gpu/texture_image_transport_surface.cc
+++ b/content/common/gpu/texture_image_transport_surface.cc
@@ -88,7 +88,7 @@ bool TextureImageTransportSurface::Initialize() {
         texture.info, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
   }
 
-  surface_ = gfx::GLSurface::CreateOffscreenGLSurface(false, gfx::Size(1, 1));
+  surface_ = manager->GetDefaultOffscreenSurface();
   if (!surface_.get())
     return false;
 
@@ -108,10 +108,8 @@ void TextureImageTransportSurface::Destroy() {
     ReleaseParentStub();
   }
 
-  if (surface_.get()) {
-    surface_->Destroy();
+  if (surface_.get())
     surface_ = NULL;
-  }
 
   helper_->Destroy();
 }
@@ -348,7 +346,7 @@ void* TextureImageTransportSurface::GetHandle() {
 }
 
 unsigned TextureImageTransportSurface::GetFormat() {
-  return surface_ ? surface_->GetFormat() : 0;
+  return surface_.get() ? surface_->GetFormat() : 0;
 }
 
 void TextureImageTransportSurface::OnSetFrontSurfaceIsProtected(
diff --git a/content/common/gpu/texture_image_transport_surface.h b/content/common/gpu/texture_image_transport_surface.h
index 19ed88c..2779d8a 100644
--- a/content/common/gpu/texture_image_transport_surface.h
+++ b/content/common/gpu/texture_image_transport_surface.h
@@ -110,7 +110,7 @@ class TextureImageTransportSurface :
   gfx::GLSurfaceHandle handle_;
   GpuCommandBufferStub* parent_stub_;
 
-  // The offscreeb surface used to make the context current. However note that
+  // The offscreen surface used to make the context current. However note that
   // the actual rendering is always redirected to an FBO.
   scoped_refptr<GLSurface> surface_;