Reland of Extend CopyTextureCHROMIUM to more ES 3.0 texture formats.

gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h

Index: gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h
diff --git a/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h b/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h
index dd705323badecb1833e85a8da0353fb8b1dbd7f3..e8664b1a4449bd3da46c57395e9e6046475d4461 100644
--- a/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h
+++ b/gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h
@@ -18,6 +18,28 @@ namespace gles2 {
 
 class GLES2Decoder;
 
+enum CopyTextureMethod {
+  // Use CopyTex{Sub}Image2D to copy from the source to the destination.
+  DIRECT_COPY,
+  // Draw from the source to the destination texture.
+  DIRECT_DRAW,
+  // Draw to an intermediate texture, and then copy to the destination texture.
+  DRAW_AND_COPY,
+  // CopyTexture isn't available.
+  NOT_COPYABLE
+};
+
+// TODOs(qiankun.miao@intel.com):
+// 1. Add readback path for RGB9_E5 and float formats (if extension isn't
+// available and they are not color-renderable).
+// 2. Support faces of cube map texture as valid dest target. The cube map
+// texture may be incomplete currently.
+// 3. Add support for levels other than 0.
+// 4. Support ALPHA, LUMINANCE and LUMINANCE_ALPHA formats on core profile.
+// 5. Update the extension doc after the whole work is done
+// in gpu/GLES2/extensions/CHROMIUM/CHROMIUM_copy_texture.txt. We probably
+// will need a ES2 version and a ES3 version.
+
 // This class encapsulates the resources required to implement the
 // GL_CHROMIUM_copy_texture extension.  The copy operation is performed
 // via glCopyTexImage2D() or a blit to a framebuffer object.
@@ -42,7 +64,8 @@ class GPU_EXPORT CopyTextureCHROMIUMResourceManager {
                      GLsizei height,
                      bool flip_y,
                      bool premultiply_alpha,
-                     bool unpremultiply_alpha);
+                     bool unpremultiply_alpha,
+                     CopyTextureMethod method);
 
   void DoCopySubTexture(const gles2::GLES2Decoder* decoder,
                         GLenum source_target,
@@ -63,7 +86,8 @@ class GPU_EXPORT CopyTextureCHROMIUMResourceManager {
                         GLsizei source_height,
                         bool flip_y,
                         bool premultiply_alpha,
-                        bool unpremultiply_alpha);
+                        bool unpremultiply_alpha,
+                        CopyTextureMethod method);
 
   void DoCopySubTextureWithTransform(const gles2::GLES2Decoder* decoder,
                                      GLenum source_target,
@@ -94,8 +118,10 @@ class GPU_EXPORT CopyTextureCHROMIUMResourceManager {
   void DoCopyTextureWithTransform(const gles2::GLES2Decoder* decoder,
                                   GLenum source_target,
                                   GLuint source_id,
+                                  GLenum source_format,
                                   GLenum dest_target,
                                   GLuint dest_id,
+                                  GLenum dest_format,
                                   GLsizei width,
                                   GLsizei height,
                                   bool flip_y,
@@ -136,8 +162,10 @@ class GPU_EXPORT CopyTextureCHROMIUMResourceManager {
   void DoCopyTextureInternal(const gles2::GLES2Decoder* decoder,
                              GLenum source_target,
                              GLuint source_id,
+                             GLenum source_format,
                              GLenum dest_target,
                              GLuint dest_id,
+                             GLenum dest_format,
                              GLint xoffset,
                              GLint yoffset,
                              GLint x,