Implement TextureImageTransportSurface using texture mailbox

content/common/gpu/client/gl_helper.cc

Index: content/common/gpu/client/gl_helper.cc
diff --git a/content/common/gpu/client/gl_helper.cc b/content/common/gpu/client/gl_helper.cc
index ef862966fad79849a252fce6cb2f18a8043fd1aa..8f37d0f58417273f25eb0845ba3c1e83736ff61b 100644
--- a/content/common/gpu/client/gl_helper.cc
+++ b/content/common/gpu/client/gl_helper.cc
@@ -271,7 +271,8 @@ class GLHelper::CopyTextureToImpl {
 
   WebKit::WebGLId CopyAndScaleTexture(WebGLId texture,
                                       const gfx::Size& src_size,
-                                      const gfx::Size& dst_size);
+                                      const gfx::Size& dst_size,
+                                      WebKit::WebGLId texture_out = 0);
 
  private:
   // A single request to CropScaleReadbackAndCleanTexture.
@@ -317,7 +318,8 @@ class GLHelper::CopyTextureToImpl {
   WebGLId ScaleTexture(WebGLId src_texture,
                        const gfx::Size& src_size,
                        const gfx::Rect& src_subrect,
-                       const gfx::Size& dst_size);
+                       const gfx::Size& dst_size,
+                       WebKit::WebGLId texture_out);
 
   // Deletes the context for GLHelperThread.
   void DeleteContextForThread();
@@ -423,8 +425,9 @@ WebGLId GLHelper::CopyTextureToImpl::ScaleTexture(
     WebGLId src_texture,
     const gfx::Size& src_size,
     const gfx::Rect& src_subrect,
-    const gfx::Size& dst_size) {
-  WebGLId dst_texture = context_->createTexture();
+    const gfx::Size& dst_size,
+    WebKit::WebGLId texture_out) {
+  WebGLId dst_texture = texture_out ? texture_out : context_->createTexture();
   {
     ScopedFramebuffer dst_framebuffer(context_, context_->createFramebuffer());
     ScopedFramebufferBinder<GL_FRAMEBUFFER> framebuffer_binder(
@@ -513,7 +516,7 @@ void GLHelper::CopyTextureToImpl::CropScaleReadbackAndCleanTexture(
     return;
   }
 
-  WebGLId texture = ScaleTexture(src_texture, src_size, src_subrect, dst_size);
+  WebGLId texture = ScaleTexture(src_texture, src_size, src_subrect, dst_size, 0);
   context_->flush();
   scoped_refptr<Request> request =
       new Request(this, texture, dst_size, out, callback);
@@ -550,8 +553,10 @@ void GLHelper::CopyTextureToImpl::ReadbackTextureSync(WebGLId texture,
 WebKit::WebGLId GLHelper::CopyTextureToImpl::CopyAndScaleTexture(
     WebGLId src_texture,
     const gfx::Size& src_size,
-    const gfx::Size& dst_size) {
-  return ScaleTexture(src_texture, src_size, gfx::Rect(src_size), dst_size);
+    const gfx::Size& dst_size,
+    WebKit::WebGLId texture_out) {
+  return ScaleTexture(src_texture, src_size, gfx::Rect(src_size), dst_size,
+                      texture_out);
 }
 
 void GLHelper::CopyTextureToImpl::ReadBackFramebuffer(
@@ -713,18 +718,22 @@ void GLHelper::ReadbackTextureSync(WebKit::WebGLId texture,
 }
 
 WebKit::WebGLId GLHelper::CopyTexture(WebKit::WebGLId texture,
-                                      const gfx::Size& size) {
+                                      const gfx::Size& size,
+                                      WebKit::WebGLId texture_out) {
   InitCopyTextToImpl();
-  return copy_texture_to_impl_->CopyAndScaleTexture(texture, size, size);
+  return copy_texture_to_impl_->CopyAndScaleTexture(texture, size, size,
+                                                    texture_out);
 }
 
 WebKit::WebGLId GLHelper::CopyAndScaleTexture(WebKit::WebGLId texture,
                                               const gfx::Size& src_size,
-                                              const gfx::Size& dst_size) {
+                                              const gfx::Size& dst_size,
+                                              WebKit::WebGLId texture_out) {
   InitCopyTextToImpl();
   return copy_texture_to_impl_->CopyAndScaleTexture(texture,
                                                     src_size,
-                                                    dst_size);
+                                                    dst_size,
+                                                    texture_out);
 }
 
 WebGLId GLHelper::CompileShaderFromSource(