Add alpha argument to glResizeCHROMIUM

This lets the compositor specify whether the backbuffer will need to be blended with the contents behind it, and if not it can use a method that uses less power.

BUG=561185
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1474873003

Cr-Commit-Position: refs/heads/master@{#362817}

23 files changed, 87 insertions, 43 deletions

diff --git a/cc/output/output_surface.cc b/cc/output/output_surface.cc
index 3430d18..d8b7962 100644
--- a/cc/output/output_surface.cc
+++ b/cc/output/output_surface.cc
@@ -257,8 +257,8 @@ void OutputSurface::Reshape(const gfx::Size& size, float scale_factor) {
   surface_size_ = size;
   device_scale_factor_ = scale_factor;
   if (context_provider_.get()) {
-    context_provider_->ContextGL()->ResizeCHROMIUM(
-        size.width(), size.height(), scale_factor);
+    context_provider_->ContextGL()->ResizeCHROMIUM(size.width(), size.height(),
+                                                   scale_factor, GL_TRUE);
   }
   if (software_device_)
     software_device_->Resize(size, scale_factor);
diff --git a/cc/test/test_gles2_interface.cc b/cc/test/test_gles2_interface.cc
index 4ebdfd3..2781712 100644
--- a/cc/test/test_gles2_interface.cc
+++ b/cc/test/test_gles2_interface.cc
@@ -379,7 +379,8 @@ GLuint TestGLES2Interface::CreateAndConsumeTextureCHROMIUM(
 
 void TestGLES2Interface::ResizeCHROMIUM(GLuint width,
                                         GLuint height,
-                                        float device_scale) {
+                                        float device_scale,
+                                        GLboolean has_alpha) {
   test_context_->reshapeWithScaleFactor(width, height, device_scale);
 }
 
diff --git a/cc/test/test_gles2_interface.h b/cc/test/test_gles2_interface.h
index 20ab007..0914810 100644
--- a/cc/test/test_gles2_interface.h
+++ b/cc/test/test_gles2_interface.h
@@ -157,7 +157,10 @@ class TestGLES2Interface : public gpu::gles2::GLES2InterfaceStub {
   GLuint CreateAndConsumeTextureCHROMIUM(GLenum target,
                                          const GLbyte* mailbox) override;
 
-  void ResizeCHROMIUM(GLuint width, GLuint height, float device_scale) override;
+  void ResizeCHROMIUM(GLuint width,
+                      GLuint height,
+                      float device_scale,
+                      GLboolean has_alpha) override;
   void LoseContextCHROMIUM(GLenum current, GLenum other) override;
   GLenum GetGraphicsResetStatusKHR() override;
 
diff --git a/gpu/GLES2/gl2extchromium.h b/gpu/GLES2/gl2extchromium.h
index 64147b4..f3c787f 100644
--- a/gpu/GLES2/gl2extchromium.h
+++ b/gpu/GLES2/gl2extchromium.h
@@ -653,8 +653,10 @@ typedef void (GL_APIENTRYP PFNGLDRAWBUFFERSEXTPROC) (
 #ifndef GL_CHROMIUM_resize
 #define GL_CHROMIUM_resize 1
 #ifdef GL_GLEXT_PROTOTYPES
-GL_APICALL void GL_APIENTRY glResizeCHROMIUM(
-    GLuint width, GLuint height, GLfloat scale_factor);
+GL_APICALL void GL_APIENTRY glResizeCHROMIUM(GLuint width,
+                                             GLuint height,
+                                             GLfloat scale_factor,
+                                             GLboolean alpha);
 #endif
 typedef void (GL_APIENTRYP PFNGLRESIZECHROMIUMPROC) (
     GLuint width, GLuint height);
diff --git a/gpu/blink/webgraphicscontext3d_impl.cc b/gpu/blink/webgraphicscontext3d_impl.cc
index 0ef42a2..a3fc0ed 100644
--- a/gpu/blink/webgraphicscontext3d_impl.cc
+++ b/gpu/blink/webgraphicscontext3d_impl.cc
@@ -223,7 +223,11 @@ bool WebGraphicsContext3DImpl::insertSyncPoint(WGC3Dbyte* sync_token) {
   return true;
 }
 
-DELEGATE_TO_GL_3(reshapeWithScaleFactor, ResizeCHROMIUM, int, int, float)
+void WebGraphicsContext3DImpl::reshapeWithScaleFactor(int width,
+                                                      int height,
+                                                      float scale) {
+  gl_->ResizeCHROMIUM(width, height, scale, true);
+}
 
 DELEGATE_TO_GL_4R(mapBufferSubDataCHROMIUM, MapBufferSubDataCHROMIUM, WGC3Denum,
                   WGC3Dintptr, WGC3Dsizeiptr, WGC3Denum, void*)
diff --git a/gpu/command_buffer/client/gles2_c_lib_autogen.h b/gpu/command_buffer/client/gles2_c_lib_autogen.h
index 7003cbc..b274a6b 100644
--- a/gpu/command_buffer/client/gles2_c_lib_autogen.h
+++ b/gpu/command_buffer/client/gles2_c_lib_autogen.h
@@ -1260,8 +1260,9 @@ void GL_APIENTRY GLES2UnmapTexSubImage2DCHROMIUM(const void* mem) {
 }
 void GL_APIENTRY GLES2ResizeCHROMIUM(GLuint width,
                                      GLuint height,
-                                     GLfloat scale_factor) {
-  gles2::GetGLContext()->ResizeCHROMIUM(width, height, scale_factor);
+                                     GLfloat scale_factor,
+                                     GLboolean alpha) {
+  gles2::GetGLContext()->ResizeCHROMIUM(width, height, scale_factor, alpha);
 }
 const GLchar* GL_APIENTRY GLES2GetRequestableExtensionsCHROMIUM() {
   return gles2::GetGLContext()->GetRequestableExtensionsCHROMIUM();
diff --git a/gpu/command_buffer/client/gles2_cmd_helper_autogen.h b/gpu/command_buffer/client/gles2_cmd_helper_autogen.h
index e2123f5..b5cf24c 100644
--- a/gpu/command_buffer/client/gles2_cmd_helper_autogen.h
+++ b/gpu/command_buffer/client/gles2_cmd_helper_autogen.h
@@ -2410,10 +2410,13 @@ void UnmapBuffer(GLenum target) {
   }
 }
 
-void ResizeCHROMIUM(GLuint width, GLuint height, GLfloat scale_factor) {
+void ResizeCHROMIUM(GLuint width,
+                    GLuint height,
+                    GLfloat scale_factor,
+                    GLboolean alpha) {
   gles2::cmds::ResizeCHROMIUM* c = GetCmdSpace<gles2::cmds::ResizeCHROMIUM>();
   if (c) {
-    c->Init(width, height, scale_factor);
+    c->Init(width, height, scale_factor, alpha);
   }
 }
 
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index 208a08b..9b52768 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -4692,12 +4692,14 @@ void GLES2Implementation::UnmapTexSubImage2DCHROMIUM(const void* mem) {
   CheckGLError();
 }
 
-void GLES2Implementation::ResizeCHROMIUM(GLuint width, GLuint height,
-                                         float scale_factor) {
+void GLES2Implementation::ResizeCHROMIUM(GLuint width,
+                                         GLuint height,
+                                         float scale_factor,
+                                         GLboolean alpha) {
   GPU_CLIENT_SINGLE_THREAD_CHECK();
-  GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glResizeCHROMIUM("
-                 << width << ", " << height << ", " << scale_factor << ")");
-  helper_->ResizeCHROMIUM(width, height, scale_factor);
+  GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glResizeCHROMIUM(" << width << ", "
+                     << height << ", " << scale_factor << ", " << alpha << ")");
+  helper_->ResizeCHROMIUM(width, height, scale_factor, alpha);
   CheckGLError();
 }
 
diff --git a/gpu/command_buffer/client/gles2_implementation_autogen.h b/gpu/command_buffer/client/gles2_implementation_autogen.h
index fc99066..0a4f886 100644
--- a/gpu/command_buffer/client/gles2_implementation_autogen.h
+++ b/gpu/command_buffer/client/gles2_implementation_autogen.h
@@ -870,7 +870,10 @@ void* MapTexSubImage2DCHROMIUM(GLenum target,
 
 void UnmapTexSubImage2DCHROMIUM(const void* mem) override;
 
-void ResizeCHROMIUM(GLuint width, GLuint height, GLfloat scale_factor) override;
+void ResizeCHROMIUM(GLuint width,
+                    GLuint height,
+                    GLfloat scale_factor,
+                    GLboolean alpha) override;
 
 const GLchar* GetRequestableExtensionsCHROMIUM() override;
 
diff --git a/gpu/command_buffer/client/gles2_implementation_unittest_autogen.h b/gpu/command_buffer/client/gles2_implementation_unittest_autogen.h
index 23f6541..e8efce0 100644
--- a/gpu/command_buffer/client/gles2_implementation_unittest_autogen.h
+++ b/gpu/command_buffer/client/gles2_implementation_unittest_autogen.h
@@ -2792,9 +2792,9 @@ TEST_F(GLES2ImplementationTest, ResizeCHROMIUM) {
     cmds::ResizeCHROMIUM cmd;
   };
   Cmds expected;
-  expected.cmd.Init(1, 2, 3);
+  expected.cmd.Init(1, 2, 3, true);
 
-  gl_->ResizeCHROMIUM(1, 2, 3);
+  gl_->ResizeCHROMIUM(1, 2, 3, true);
   EXPECT_EQ(0, memcmp(&expected, commands_, sizeof(expected)));
 }
 
diff --git a/gpu/command_buffer/client/gles2_interface_autogen.h b/gpu/command_buffer/client/gles2_interface_autogen.h
index 9edbc49..77872e7 100644
--- a/gpu/command_buffer/client/gles2_interface_autogen.h
+++ b/gpu/command_buffer/client/gles2_interface_autogen.h
@@ -646,7 +646,8 @@ virtual void* MapTexSubImage2DCHROMIUM(GLenum target,
 virtual void UnmapTexSubImage2DCHROMIUM(const void* mem) = 0;
 virtual void ResizeCHROMIUM(GLuint width,
                             GLuint height,
-                            GLfloat scale_factor) = 0;
+                            GLfloat scale_factor,
+                            GLboolean alpha) = 0;
 virtual const GLchar* GetRequestableExtensionsCHROMIUM() = 0;
 virtual void RequestExtensionCHROMIUM(const char* extension) = 0;
 virtual void GetProgramInfoCHROMIUM(GLuint program,
diff --git a/gpu/command_buffer/client/gles2_interface_stub_autogen.h b/gpu/command_buffer/client/gles2_interface_stub_autogen.h
index bc478cb..5469525 100644
--- a/gpu/command_buffer/client/gles2_interface_stub_autogen.h
+++ b/gpu/command_buffer/client/gles2_interface_stub_autogen.h
@@ -623,7 +623,10 @@ void* MapTexSubImage2DCHROMIUM(GLenum target,
                                GLenum type,
                                GLenum access) override;
 void UnmapTexSubImage2DCHROMIUM(const void* mem) override;
-void ResizeCHROMIUM(GLuint width, GLuint height, GLfloat scale_factor) override;
+void ResizeCHROMIUM(GLuint width,
+                    GLuint height,
+                    GLfloat scale_factor,
+                    GLboolean alpha) override;
 const GLchar* GetRequestableExtensionsCHROMIUM() override;
 void RequestExtensionCHROMIUM(const char* extension) override;
 void GetProgramInfoCHROMIUM(GLuint program,
diff --git a/gpu/command_buffer/client/gles2_interface_stub_impl_autogen.h b/gpu/command_buffer/client/gles2_interface_stub_impl_autogen.h
index 4e3a712..867652f 100644
--- a/gpu/command_buffer/client/gles2_interface_stub_impl_autogen.h
+++ b/gpu/command_buffer/client/gles2_interface_stub_impl_autogen.h
@@ -860,7 +860,8 @@ void* GLES2InterfaceStub::MapTexSubImage2DCHROMIUM(GLenum /* target */,
 void GLES2InterfaceStub::UnmapTexSubImage2DCHROMIUM(const void* /* mem */) {}
 void GLES2InterfaceStub::ResizeCHROMIUM(GLuint /* width */,
                                         GLuint /* height */,
-                                        GLfloat /* scale_factor */) {}
+                                        GLfloat /* scale_factor */,
+                                        GLboolean /* alpha */) {}
 const GLchar* GLES2InterfaceStub::GetRequestableExtensionsCHROMIUM() {
   return 0;
 }
diff --git a/gpu/command_buffer/client/gles2_trace_implementation_autogen.h b/gpu/command_buffer/client/gles2_trace_implementation_autogen.h
index 27923ea..209215e 100644
--- a/gpu/command_buffer/client/gles2_trace_implementation_autogen.h
+++ b/gpu/command_buffer/client/gles2_trace_implementation_autogen.h
@@ -623,7 +623,10 @@ void* MapTexSubImage2DCHROMIUM(GLenum target,
                                GLenum type,
                                GLenum access) override;
 void UnmapTexSubImage2DCHROMIUM(const void* mem) override;
-void ResizeCHROMIUM(GLuint width, GLuint height, GLfloat scale_factor) override;
+void ResizeCHROMIUM(GLuint width,
+                    GLuint height,
+                    GLfloat scale_factor,
+                    GLboolean alpha) override;
 const GLchar* GetRequestableExtensionsCHROMIUM() override;
 void RequestExtensionCHROMIUM(const char* extension) override;
 void GetProgramInfoCHROMIUM(GLuint program,
diff --git a/gpu/command_buffer/client/gles2_trace_implementation_impl_autogen.h b/gpu/command_buffer/client/gles2_trace_implementation_impl_autogen.h
index 1fc343f..77c6ab6 100644
--- a/gpu/command_buffer/client/gles2_trace_implementation_impl_autogen.h
+++ b/gpu/command_buffer/client/gles2_trace_implementation_impl_autogen.h
@@ -1837,9 +1837,10 @@ void GLES2TraceImplementation::UnmapTexSubImage2DCHROMIUM(const void* mem) {
 
 void GLES2TraceImplementation::ResizeCHROMIUM(GLuint width,
                                               GLuint height,
-                                              GLfloat scale_factor) {
+                                              GLfloat scale_factor,
+                                              GLboolean alpha) {
   TRACE_EVENT_BINARY_EFFICIENT0("gpu", "GLES2Trace::ResizeCHROMIUM");
-  gl_->ResizeCHROMIUM(width, height, scale_factor);
+  gl_->ResizeCHROMIUM(width, height, scale_factor, alpha);
 }
 
 const GLchar* GLES2TraceImplementation::GetRequestableExtensionsCHROMIUM() {
diff --git a/gpu/command_buffer/cmd_buffer_functions.txt b/gpu/command_buffer/cmd_buffer_functions.txt
index fe6e9e9..42ed5f5 100644
--- a/gpu/command_buffer/cmd_buffer_functions.txt
+++ b/gpu/command_buffer/cmd_buffer_functions.txt
@@ -265,7 +265,7 @@ GL_APICALL void*        GL_APIENTRY glMapBufferRange (GLenumBufferTarget target,
 GL_APICALL GLboolean    GL_APIENTRY glUnmapBuffer (GLenumBufferTarget target);
 GL_APICALL void*        GL_APIENTRY glMapTexSubImage2DCHROMIUM (GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLenum type, GLenum access);
 GL_APICALL void         GL_APIENTRY glUnmapTexSubImage2DCHROMIUM (const void* mem);
-GL_APICALL void         GL_APIENTRY glResizeCHROMIUM (GLuint width, GLuint height, GLfloat scale_factor);
+GL_APICALL void         GL_APIENTRY glResizeCHROMIUM (GLuint width, GLuint height, GLfloat scale_factor, GLboolean alpha);
 GL_APICALL const GLchar* GL_APIENTRY glGetRequestableExtensionsCHROMIUM (void);
 GL_APICALL void         GL_APIENTRY glRequestExtensionCHROMIUM (const char* extension);
 GL_APICALL void         GL_APIENTRY glGetProgramInfoCHROMIUM (GLidProgram program, GLsizeiNotNegative bufsize, GLsizei* size, void* info);
diff --git a/gpu/command_buffer/common/gles2_cmd_format_autogen.h b/gpu/command_buffer/common/gles2_cmd_format_autogen.h
index 95bf3a8..b26cea0 100644
--- a/gpu/command_buffer/common/gles2_cmd_format_autogen.h
+++ b/gpu/command_buffer/common/gles2_cmd_format_autogen.h
@@ -11899,15 +11899,23 @@ struct ResizeCHROMIUM {
 
   void SetHeader() { header.SetCmd<ValueType>(); }
 
-  void Init(GLuint _width, GLuint _height, GLfloat _scale_factor) {
+  void Init(GLuint _width,
+            GLuint _height,
+            GLfloat _scale_factor,
+            GLboolean _alpha) {
     SetHeader();
     width = _width;
     height = _height;
     scale_factor = _scale_factor;
+    alpha = _alpha;
   }
 
-  void* Set(void* cmd, GLuint _width, GLuint _height, GLfloat _scale_factor) {
-    static_cast<ValueType*>(cmd)->Init(_width, _height, _scale_factor);
+  void* Set(void* cmd,
+            GLuint _width,
+            GLuint _height,
+            GLfloat _scale_factor,
+            GLboolean _alpha) {
+    static_cast<ValueType*>(cmd)->Init(_width, _height, _scale_factor, _alpha);
     return NextCmdAddress<ValueType>(cmd);
   }
 
@@ -11915,10 +11923,11 @@ struct ResizeCHROMIUM {
   uint32_t width;
   uint32_t height;
   float scale_factor;
+  uint32_t alpha;
 };
 
-static_assert(sizeof(ResizeCHROMIUM) == 16,
-              "size of ResizeCHROMIUM should be 16");
+static_assert(sizeof(ResizeCHROMIUM) == 20,
+              "size of ResizeCHROMIUM should be 20");
 static_assert(offsetof(ResizeCHROMIUM, header) == 0,
               "offset of ResizeCHROMIUM header should be 0");
 static_assert(offsetof(ResizeCHROMIUM, width) == 4,
@@ -11927,6 +11936,8 @@ static_assert(offsetof(ResizeCHROMIUM, height) == 8,
               "offset of ResizeCHROMIUM height should be 8");
 static_assert(offsetof(ResizeCHROMIUM, scale_factor) == 12,
               "offset of ResizeCHROMIUM scale_factor should be 12");
+static_assert(offsetof(ResizeCHROMIUM, alpha) == 16,
+              "offset of ResizeCHROMIUM alpha should be 16");
 
 struct GetRequestableExtensionsCHROMIUM {
   typedef GetRequestableExtensionsCHROMIUM ValueType;
diff --git a/gpu/command_buffer/common/gles2_cmd_format_test_autogen.h b/gpu/command_buffer/common/gles2_cmd_format_test_autogen.h
index b165447..95a8ab8 100644
--- a/gpu/command_buffer/common/gles2_cmd_format_test_autogen.h
+++ b/gpu/command_buffer/common/gles2_cmd_format_test_autogen.h
@@ -4007,14 +4007,16 @@ TEST_F(GLES2FormatTest, UnmapBuffer) {
 
 TEST_F(GLES2FormatTest, ResizeCHROMIUM) {
   cmds::ResizeCHROMIUM& cmd = *GetBufferAs<cmds::ResizeCHROMIUM>();
-  void* next_cmd = cmd.Set(&cmd, static_cast<GLuint>(11),
-                           static_cast<GLuint>(12), static_cast<GLfloat>(13));
+  void* next_cmd =
+      cmd.Set(&cmd, static_cast<GLuint>(11), static_cast<GLuint>(12),
+              static_cast<GLfloat>(13), static_cast<GLboolean>(14));
   EXPECT_EQ(static_cast<uint32_t>(cmds::ResizeCHROMIUM::kCmdId),
             cmd.header.command);
   EXPECT_EQ(sizeof(cmd), cmd.header.size * 4u);
   EXPECT_EQ(static_cast<GLuint>(11), cmd.width);
   EXPECT_EQ(static_cast<GLuint>(12), cmd.height);
   EXPECT_EQ(static_cast<GLfloat>(13), cmd.scale_factor);
+  EXPECT_EQ(static_cast<GLboolean>(14), cmd.alpha);
   CheckBytesWrittenMatchesExpectedSize(next_cmd, sizeof(cmd));
 }
 
diff --git a/gpu/command_buffer/tests/gl_texture_mailbox_unittest.cc b/gpu/command_buffer/tests/gl_texture_mailbox_unittest.cc
index 3ceb5ff..6025427 100644
--- a/gpu/command_buffer/tests/gl_texture_mailbox_unittest.cc
+++ b/gpu/command_buffer/tests/gl_texture_mailbox_unittest.cc
@@ -341,7 +341,7 @@ TEST_F(GLTextureMailboxTest, ProduceFrontBuffer) {
   EXPECT_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
 
   gl2_.MakeCurrent();
-  glResizeCHROMIUM(10, 10, 1);
+  glResizeCHROMIUM(10, 10, 1, true);
   glClearColor(1, 0, 0, 1);
   glClear(GL_COLOR_BUFFER_BIT);
   ::gles2::GetGLContext()->SwapBuffers();
@@ -430,7 +430,7 @@ TEST_F(GLTextureMailboxTest, ProduceFrontBufferMultipleContexts) {
 
   for (size_t i = 0; i < 2; ++i) {
     other_gl[i].MakeCurrent();
-    glResizeCHROMIUM(10, 10, 1);
+    glResizeCHROMIUM(10, 10, 1, true);
     glClearColor(1-i%2, i%2, 0, 1);
     glClear(GL_COLOR_BUFFER_BIT);
     ::gles2::GetGLContext()->SwapBuffers();
diff --git a/mojo/gpu/mojo_gles2_impl_autogen.cc b/mojo/gpu/mojo_gles2_impl_autogen.cc
index 8b57228..8f817e3 100644
--- a/mojo/gpu/mojo_gles2_impl_autogen.cc
+++ b/mojo/gpu/mojo_gles2_impl_autogen.cc
@@ -1410,9 +1410,10 @@ void MojoGLES2Impl::UnmapTexSubImage2DCHROMIUM(const void* mem) {
 }
 void MojoGLES2Impl::ResizeCHROMIUM(GLuint width,
                                    GLuint height,
-                                   GLfloat scale_factor) {
+                                   GLfloat scale_factor,
+                                   GLboolean alpha) {
   MojoGLES2MakeCurrent(context_);
-  glResizeCHROMIUM(width, height, scale_factor);
+  glResizeCHROMIUM(width, height, scale_factor, alpha);
 }
 const GLchar* MojoGLES2Impl::GetRequestableExtensionsCHROMIUM() {
   MojoGLES2MakeCurrent(context_);
diff --git a/mojo/gpu/mojo_gles2_impl_autogen.h b/mojo/gpu/mojo_gles2_impl_autogen.h
index 4b43bb97..e207ca4 100644
--- a/mojo/gpu/mojo_gles2_impl_autogen.h
+++ b/mojo/gpu/mojo_gles2_impl_autogen.h
@@ -649,7 +649,8 @@ class MojoGLES2Impl : public gpu::gles2::GLES2Interface {
   void UnmapTexSubImage2DCHROMIUM(const void* mem) override;
   void ResizeCHROMIUM(GLuint width,
                       GLuint height,
-                      GLfloat scale_factor) override;
+                      GLfloat scale_factor,
+                      GLboolean alpha) override;
   const GLchar* GetRequestableExtensionsCHROMIUM() override;
   void RequestExtensionCHROMIUM(const char* extension) override;
   void GetProgramInfoCHROMIUM(GLuint program,
diff --git a/mojo/public/c/gles2/gles2_call_visitor_chromium_extension_autogen.h b/mojo/public/c/gles2/gles2_call_visitor_chromium_extension_autogen.h
index c9b1c0a..a6c8585 100644
--- a/mojo/public/c/gles2/gles2_call_visitor_chromium_extension_autogen.h
+++ b/mojo/public/c/gles2/gles2_call_visitor_chromium_extension_autogen.h
@@ -140,10 +140,11 @@ VISIT_GL_CALL(
      GLenum access),
     (target, level, xoffset, yoffset, width, height, format, type, access))
 VISIT_GL_CALL(UnmapTexSubImage2DCHROMIUM, void, (const void* mem), (mem))
-VISIT_GL_CALL(ResizeCHROMIUM,
-              void,
-              (GLuint width, GLuint height, GLfloat scale_factor),
-              (width, height, scale_factor))
+VISIT_GL_CALL(
+    ResizeCHROMIUM,
+    void,
+    (GLuint width, GLuint height, GLfloat scale_factor, GLboolean alpha),
+    (width, height, scale_factor, alpha))
 VISIT_GL_CALL(GetRequestableExtensionsCHROMIUM, const GLchar*, (), ())
 VISIT_GL_CALL(RequestExtensionCHROMIUM,
               void,
diff --git a/ppapi/shared_impl/ppb_graphics_3d_shared.cc b/ppapi/shared_impl/ppb_graphics_3d_shared.cc
index 854bf51..3dadacb 100644
--- a/ppapi/shared_impl/ppb_graphics_3d_shared.cc
+++ b/ppapi/shared_impl/ppb_graphics_3d_shared.cc
@@ -48,7 +48,7 @@ int32_t PPB_Graphics3D_Shared::ResizeBuffers(int32_t width, int32_t height) {
   if ((width < 0) || (height < 0))
     return PP_ERROR_BADARGUMENT;
 
-  gles2_impl()->ResizeCHROMIUM(width, height, 1.f);
+  gles2_impl()->ResizeCHROMIUM(width, height, 1.f, true);
   // TODO(alokp): Check if resize succeeded and return appropriate error code.
   return PP_OK;
 }