Revert of Initialize buffers before allowing access to them.

gpu/command_buffer/service/buffer_manager.h

Index: gpu/command_buffer/service/buffer_manager.h
diff --git a/gpu/command_buffer/service/buffer_manager.h b/gpu/command_buffer/service/buffer_manager.h
index 845824c56679ceaf6cfce6d27ddd8a8e5cc34a9f..bb69e7dfe0c2f2603a82f662b039868c4f0a0de4 100644
--- a/gpu/command_buffer/service/buffer_manager.h
+++ b/gpu/command_buffer/service/buffer_manager.h
@@ -78,8 +78,9 @@
   // Check if an offset, size range is valid for the current buffer.
   bool CheckRange(GLintptr offset, GLsizeiptr size) const;
 
-  // Sets a range of this buffer's shadowed data.
-  void SetRange(GLintptr offset, GLsizeiptr size, const GLvoid * data);
+  // Sets a range of this buffer's shadowed data. Returns false if offset/size
+  // is out of range.
+  bool SetRange(GLintptr offset, GLsizeiptr size, const GLvoid * data);
 
   bool IsDeleted() const {
     return deleted_;
@@ -95,8 +96,15 @@
 
   void SetMappedRange(GLintptr offset, GLsizeiptr size, GLenum access,
                       void* pointer, scoped_refptr<gpu::Buffer> shm,
-                      unsigned int shm_offset);
-  void RemoveMappedRange();
+                      unsigned int shm_offset) {
+    mapped_range_.reset(
+        new MappedRange(offset, size, access, pointer, shm, shm_offset));
+  }
+
+  void RemoveMappedRange() {
+    mapped_range_.reset(nullptr);
+  }
+
   const MappedRange* GetMappedRange() const {
     return mapped_range_.get();
   }
@@ -298,30 +306,6 @@
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;
 
-  // Validate if a buffer is bound at target, if it's unmapped, if it's
-  // large enough. Return the buffer bound to |target| if access is granted;
-  // return nullptr if a GL error is generated.
-  Buffer* RequestBufferAccess(ContextState* context_state,
-                              GLenum target,
-                              GLintptr offset,
-                              GLsizeiptr size,
-                              const char* func_name);
-  // Same as above, but assume to access the entire buffer.
-  Buffer* RequestBufferAccess(ContextState* context_state,
-                              GLenum target,
-                              const char* func_name);
-  // Same as above, but it can be any buffer rather than the buffer bound to
-  // |target|. Return true if access is granted; return false if a GL error is
-  // generated.
-  bool RequestBufferAccess(ErrorState* error_state,
-                           Buffer* buffer,
-                           const char* func_name,
-                           const char* message_tag);
-
-  uint32_t mapped_buffer_count() const {
-    return mapped_buffer_count_;
-  }
-
  private:
   friend class Buffer;
   friend class TestHelper;  // Needs access to DoBufferData.
@@ -334,6 +318,7 @@
   // Does a glBufferSubData and updates the appropriate accounting.
   // Assumes the values have already been validated.
   void DoBufferSubData(
+      ErrorState* error_state,
       Buffer* buffer,
       GLenum target,
       GLintptr offset,
@@ -372,9 +357,6 @@
                GLenum usage,
                bool use_shadow);
 
-  void IncreaseMappedBufferCount();
-  void DecreaseMappedBufferCount();
-
   std::unique_ptr<MemoryTypeTracker> memory_type_tracker_;
   MemoryTracker* memory_tracker_;
   scoped_refptr<FeatureInfo> feature_info_;
@@ -401,10 +383,6 @@
   bool lost_context_;
   bool use_client_side_arrays_for_stream_buffers_;
 
-  // Keep track of total mapped buffer count. In most use cases it should be 0,
-  // so we could bypass checking each individual buffer as an optimization.
-  uint32_t mapped_buffer_count_;
-
   DISALLOW_COPY_AND_ASSIGN(BufferManager);
 };