Implement transform/clip support for Android WebView.

content/renderer/gpu/mailbox_output_surface.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.
 
 #include "content/renderer/gpu/mailbox_output_surface.h"
 
 #include "base/logging.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
 #include "cc/output/gl_frame_data.h"
@@ skipping 27 matching lines @@
   }
 }
 
 void MailboxOutputSurface::EnsureBackbuffer() {
   is_backbuffer_discarded_ = false;
 
   if (!current_backing_.texture_id) {
     // Find a texture of matching size to recycle.
     while (!returned_textures_.empty()) {
       TransferableFrame& texture = returned_textures_.front();
-      if (texture.size == size_) {
+      if (texture.size == surface_size_) {
         current_backing_ = texture;
         ConsumeTexture(texture);
         returned_textures_.pop();
         break;
       }
 
       ConsumeTexture(texture);
       context3d_->deleteTexture(texture.texture_id);
       returned_textures_.pop();
     }
 
     if (!current_backing_.texture_id) {
       current_backing_.texture_id = context3d_->createTexture();
-      current_backing_.size = size_;
+      current_backing_.size = surface_size_;
       context3d_->genMailboxCHROMIUM(current_backing_.mailbox.name);
       context3d_->bindTexture(GL_TEXTURE_2D, current_backing_.texture_id);
       context3d_->texParameteri(
           GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
       context3d_->texParameteri(
           GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
       context3d_->texParameteri(
           GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
       context3d_->texParameteri(
           GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
       context3d_->texImage2D(
-          GL_TEXTURE_2D, 0, GL_RGBA, size_.width(), size_.height(), 0,
+          GL_TEXTURE_2D, 0, GL_RGBA,
+          surface_size_.width(), surface_size_.height(), 0,
           GL_RGBA, GL_UNSIGNED_BYTE, NULL);
     }
   }
 }
 
 void MailboxOutputSurface::DiscardBackbuffer() {
   is_backbuffer_discarded_ = true;
 
   if (current_backing_.texture_id) {
     context3d_->deleteTexture(current_backing_.texture_id);
     current_backing_ = TransferableFrame();
   }
 
   while (!returned_textures_.empty()) {
     const TransferableFrame& frame = returned_textures_.front();
     ConsumeTexture(frame);
     context3d_->deleteTexture(frame.texture_id);
     returned_textures_.pop();
   }
 
   if (fbo_) {
     context3d_->bindFramebuffer(GL_FRAMEBUFFER, fbo_);
     context3d_->deleteFramebuffer(fbo_);
     fbo_ = 0;
   }
 }
 
 void MailboxOutputSurface::Reshape(gfx::Size size, float scale_factor) {
-  if (size == size_)
+  if (size == surface_size_)
     return;
 
-  size_ = size;
+  surface_size_ = size;

[piman, 2013/06/05 00:52:08]

Also set device_scale_factor_ so that it doesn't get out-of-date.

Not the fault of this CL, but implementation inheritance here is very messy &
fragile. We should have separated out the OutputSurface interface from the
common backed-by-a-context's-default-surface implementation.

   DiscardBackbuffer();
   EnsureBackbuffer();
 }
 
 void MailboxOutputSurface::BindFramebuffer() {
   EnsureBackbuffer();
   DCHECK(current_backing_.texture_id);
 
   if (!fbo_)
     fbo_ = context3d_->createFramebuffer();
   context3d_->bindFramebuffer(GL_FRAMEBUFFER, fbo_);
   context3d_->framebufferTexture2D(
       GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
       current_backing_.texture_id, 0);
 }
 
 void MailboxOutputSurface::SendFrameToParentCompositor(
     cc::CompositorFrame* frame) {
   frame->gl_frame_data.reset(new GLFrameData());
 
-  DCHECK(!size_.IsEmpty());
-  DCHECK(size_ == current_backing_.size);
+  DCHECK(!surface_size_.IsEmpty());
+  DCHECK(surface_size_ == current_backing_.size);
   DCHECK(!current_backing_.mailbox.IsZero());
 
   context3d_->framebufferTexture2D(
       GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 0, 0);
   context3d_->bindFramebuffer(GL_FRAMEBUFFER, 0);
   context3d_->bindTexture(GL_TEXTURE_2D, current_backing_.texture_id);
   context3d_->produceTextureCHROMIUM(
       GL_TEXTURE_2D, current_backing_.mailbox.name);
   frame->gl_frame_data->mailbox = current_backing_.mailbox;
   frame->gl_frame_data->size = current_backing_.size;
@@ skipping 64 matching lines @@
   context3d_->bindTexture(GL_TEXTURE_2D, frame.texture_id);
   context3d_->consumeTextureCHROMIUM(GL_TEXTURE_2D, frame.mailbox.name);
 }
 
 size_t MailboxOutputSurface::GetNumAcksPending() {
   DCHECK(pending_textures_.size());
   return pending_textures_.size() - 1;
 }
 
 }  // namespace content