Validate fbo color image format and fragment shader output variable type.

gpu/command_buffer/service/framebuffer_manager.h

Index: gpu/command_buffer/service/framebuffer_manager.h
diff --git a/gpu/command_buffer/service/framebuffer_manager.h b/gpu/command_buffer/service/framebuffer_manager.h
index 2337843f68ef929b447efbf1cb4c81f7a4658d44..b632db348dcc5e902d1750a2ad096401331776e1 100644
--- a/gpu/command_buffer/service/framebuffer_manager.h
+++ b/gpu/command_buffer/service/framebuffer_manager.h
@@ -16,6 +16,7 @@
 #include "base/memory/ref_counted.h"
 #include "gpu/command_buffer/service/context_group.h"
 #include "gpu/command_buffer/service/gl_utils.h"
+#include "gpu/command_buffer/service/shader_manager.h"
 #include "gpu/gpu_export.h"
 
 namespace gpu {
@@ -180,9 +181,8 @@ class GPU_EXPORT Framebuffer : public base::RefCounted<Framebuffer> {
   // Return true if the DrawBuffers() is actually called.
   bool PrepareDrawBuffersForClear() const;
 
-  // Restore draw buffers states that have been changed in
-  // PrepareDrawBuffersForClear().
-  void RestoreDrawBuffersAfterClear() const;
+  // Restore draw buffers states that have been changed.
+  void RestoreDrawBuffers() const;
 
   // Return true if any draw buffers has an alpha channel.
   bool HasAlphaMRT() const;
@@ -199,6 +199,11 @@ class GPU_EXPORT Framebuffer : public base::RefCounted<Framebuffer> {
     return read_buffer_;
   }
 
+  const std::vector<ShaderVariableBaseType>& GetColorAttachmentBaseTypes(
+      ) const {
+    return color_attachment_base_types_;
+  }
+
  private:
   friend class FramebufferManager;
   friend class base::RefCounted<Framebuffer>;
@@ -213,6 +218,7 @@ class GPU_EXPORT Framebuffer : public base::RefCounted<Framebuffer> {
     bool cleared);
 
   void MarkAsComplete(unsigned state_id) {
+    UpdateColorAttachmentBaseTypes();
     framebuffer_complete_state_count_id_ = state_id;
   }
 
@@ -220,6 +226,13 @@ class GPU_EXPORT Framebuffer : public base::RefCounted<Framebuffer> {
     return framebuffer_complete_state_count_id_;
   }
 
+  // Cache color attachments' base types (FLOAT, INT, UINT) for optimization
+  // purpose. If an attachment point has no image, it's set as UNDEFINED_TYPE.
+  // This call is only valid on a complete fbo.
+  void UpdateColorAttachmentBaseTypes();
+
+  void ResetColorAttachmentBaseTypes();
+
   // The managers that owns this.
   FramebufferManager* manager_;
 
@@ -240,6 +253,8 @@ class GPU_EXPORT Framebuffer : public base::RefCounted<Framebuffer> {
 
   std::unique_ptr<GLenum[]> draw_buffers_;
 
+  std::vector<ShaderVariableBaseType> color_attachment_base_types_;
+
   GLenum read_buffer_;
 
   DISALLOW_COPY_AND_ASSIGN(Framebuffer);