Chrome displays the wrong thing if FBO is left bound in WebGL.

Fix a webgl bug in command buffer: if a user created fbo is bound, compositor doesn't get the correct frame.  The issue is that currently multisampled framebuffer blit is incorrectly skipped if a user created fbo is bound.

BUG=79750
TEST=bots green, test case attached in bug 79750 behaves correctly.
Review URL: http://codereview.chromium.org/6873099

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@82201 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 12 insertions, 9 deletions

diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 42f9a2b..65b2e56 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -173,11 +173,12 @@ class ScopedFrameBufferBinder {
 };
 
 // Temporarily changes a decoder's bound frame buffer to a resolved version of
-// the multisampled offscreen render buffer if and only if that buffer is
-// currently bound and is multisampled.
+// the multisampled offscreen render buffer if that buffer is multisampled, and,
+// if it is bound or enforce_internal_framebuffer is true.
 class ScopedResolvedFrameBufferBinder {
  public:
-  explicit ScopedResolvedFrameBufferBinder(GLES2DecoderImpl* decoder);
+  explicit ScopedResolvedFrameBufferBinder(GLES2DecoderImpl* decoder,
+                                           bool enforce_internal_framebuffer);
   ~ScopedResolvedFrameBufferBinder();
 
  private:
@@ -1527,10 +1528,12 @@ ScopedFrameBufferBinder::~ScopedFrameBufferBinder() {
 }
 
 ScopedResolvedFrameBufferBinder::ScopedResolvedFrameBufferBinder(
-    GLES2DecoderImpl* decoder) : decoder_(decoder) {
+    GLES2DecoderImpl* decoder, bool enforce_internal_framebuffer)
+    : decoder_(decoder) {
   resolve_and_bind_ = (decoder_->offscreen_target_frame_buffer_.get() &&
                        decoder_->IsOffscreenBufferMultisampled() &&
-                       !decoder_->bound_read_framebuffer_.get());
+                       (!decoder_->bound_read_framebuffer_.get() ||
+                        enforce_internal_framebuffer));
   if (!resolve_and_bind_)
     return;
 
@@ -4961,7 +4964,7 @@ error::Error GLES2DecoderImpl::HandleReadPixels(
 
   CopyRealGLErrorsToWrapper();
 
-  ScopedResolvedFrameBufferBinder binder(this);
+  ScopedResolvedFrameBufferBinder binder(this, false);
 
   // Get the size of the current fbo or backbuffer.
   gfx::Size max_size = GetBoundReadFrameBufferSize();
@@ -5731,7 +5734,7 @@ void GLES2DecoderImpl::DoCopyTexImage2D(
   }
 
   CopyRealGLErrorsToWrapper();
-  ScopedResolvedFrameBufferBinder binder(this);
+  ScopedResolvedFrameBufferBinder binder(this, false);
   gfx::Size size = GetBoundReadFrameBufferSize();
 
   // Clip to size to source dimensions
@@ -5815,7 +5818,7 @@ void GLES2DecoderImpl::DoCopyTexSubImage2D(
     return;
   }
 
-  ScopedResolvedFrameBufferBinder binder(this);
+  ScopedResolvedFrameBufferBinder binder(this, false);
   gfx::Size size = GetBoundReadFrameBufferSize();
   GLint copyX = 0;
   GLint copyY = 0;
@@ -6337,7 +6340,7 @@ error::Error GLES2DecoderImpl::HandleSwapBuffers(
     if (IsOffscreenBufferMultisampled()) {
       // For multisampled buffers, bind the resolved frame buffer so that
       // callbacks can call ReadPixels or CopyTexImage2D.
-      ScopedResolvedFrameBufferBinder binder(this);
+      ScopedResolvedFrameBufferBinder binder(this, true);
       if (swap_buffers_callback_.get()) {
         swap_buffers_callback_->Run();
       }