Fix blits from multisampled renderbuffers to alpha:false WebGL back buffer.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index b90974062192801e6f5a9a29d000204649798c14..db2c9d22c142c3fa90d8e93ba069e37e30e79b9b 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -1041,6 +1041,14 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
   void DoBindTexImage2DCHROMIUM(
       GLenum target,
       GLint image_id);
+  void DoBindTexImage2DWithInternalformatCHROMIUM(GLenum target,
+                                                  GLenum internalformat,
+                                                  GLint image_id);
+  // Common implementation of DoBindTexImage2DCHROMIUM entry points.
+  void BindTexImage2DCHROMIUMImpl(const char* function_name,
+                                  GLenum target,
+                                  GLenum internalformat,
+                                  GLint image_id);
   void DoReleaseTexImage2DCHROMIUM(
       GLenum target,
       GLint image_id);
@@ -17763,10 +17771,26 @@ void GLES2DecoderImpl::DoBindTexImage2DCHROMIUM(
     GLenum target, GLint image_id) {
   TRACE_EVENT0("gpu", "GLES2DecoderImpl::DoBindTexImage2DCHROMIUM");
 
+  BindTexImage2DCHROMIUMImpl("glBindTexImage2DCHROMIUM", target, 0, image_id);
+}
+
+void GLES2DecoderImpl::DoBindTexImage2DWithInternalformatCHROMIUM(
+    GLenum target,
+    GLenum internalformat,
+    GLint image_id) {
+  TRACE_EVENT0("gpu",
+               "GLES2DecoderImpl::DoBindTexImage2DWithInternalformatCHROMIUM");
+
+  BindTexImage2DCHROMIUMImpl("glBindTexImage2DWithInternalformatCHROMIUM",
+                             target, internalformat, image_id);
+}
+
+void GLES2DecoderImpl::BindTexImage2DCHROMIUMImpl(const char* function_name,
+                                                  GLenum target,
+                                                  GLenum internalformat,
+                                                  GLint image_id) {
   if (target == GL_TEXTURE_CUBE_MAP) {
-    LOCAL_SET_GL_ERROR(
-        GL_INVALID_ENUM,
-        "glBindTexImage2DCHROMIUM", "invalid target");
+    LOCAL_SET_GL_ERROR(GL_INVALID_ENUM, function_name, "invalid target");
     return;
   }
 
@@ -17775,17 +17799,14 @@ void GLES2DecoderImpl::DoBindTexImage2DCHROMIUM(
   TextureRef* texture_ref =
       texture_manager()->GetTextureInfoForTargetUnlessDefault(&state_, target);
   if (!texture_ref) {
-    LOCAL_SET_GL_ERROR(
-        GL_INVALID_OPERATION,
-        "glBindTexImage2DCHROMIUM", "no texture bound");
+    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, function_name, "no texture bound");
     return;
   }
 
   gl::GLImage* image = image_manager()->LookupImage(image_id);
   if (!image) {
-    LOCAL_SET_GL_ERROR(
-        GL_INVALID_OPERATION,
-        "glBindTexImage2DCHROMIUM", "no image found with the given ID");
+    LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION, function_name,
+                       "no image found with the given ID");
     return;
   }
 
@@ -17797,15 +17818,22 @@ void GLES2DecoderImpl::DoBindTexImage2DCHROMIUM(
 
     // Note: We fallback to using CopyTexImage() before the texture is used
     // when BindTexImage() fails.
-    if (image->BindTexImage(target))
-      image_state = Texture::BOUND;
+    if (internalformat) {
+      if (image->BindTexImageWithInternalformat(target, internalformat))
+        image_state = Texture::BOUND;
+    } else {
+      if (image->BindTexImage(target))
+        image_state = Texture::BOUND;
+    }
   }
 
   gfx::Size size = image->GetSize();
-  GLenum internalformat = image->GetInternalFormat();
-  texture_manager()->SetLevelInfo(
-      texture_ref, target, 0, internalformat, size.width(), size.height(), 1, 0,
-      internalformat, GL_UNSIGNED_BYTE, gfx::Rect(size));
+  GLenum texture_internalformat =
+      internalformat ? internalformat : image->GetInternalFormat();
+  texture_manager()->SetLevelInfo(texture_ref, target, 0,
+                                  texture_internalformat, size.width(),
+                                  size.height(), 1, 0, texture_internalformat,
+                                  GL_UNSIGNED_BYTE, gfx::Rect(size));
   texture_manager()->SetLevelImage(texture_ref, target, 0, image, image_state);
 }