Always apply UniformMatrix4fvStreamTextureMatrixCHROMIUM matrix argument.

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 f28cc4387e7832e07bdf8335f303ff646fd0293c..18a74226eb05871b9d46c01e4e714c01ee932384 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -7617,16 +7617,9 @@ void GLES2DecoderImpl::DoUniformMatrix4fv(
 void GLES2DecoderImpl::DoUniformMatrix4fvStreamTextureMatrixCHROMIUM(
     GLint fake_location,
     GLboolean transpose,
-    const GLfloat* default_value) {
+    const GLfloat* transform) {
   float gl_matrix[16];
 
-  // If we can't get a matrix from the texture, then use a default.
-  // TODO(liberato): remove |default_value| and replace with an identity matrix.
-  // It is only present as a transitionary step until StreamTexture supplies
-  // the matrix via GLImage.  Once that happens, GLRenderer can quit sending
-  // in a default.
-  memcpy(gl_matrix, default_value, sizeof(gl_matrix));
-
   // This refers to the bound external texture on the active unit.
   TextureUnit& unit = state_.texture_units[state_.active_texture_unit];
   if (TextureRef* texture_ref = unit.bound_texture_external_oes.get()) {
@@ -7634,6 +7627,19 @@ void GLES2DecoderImpl::DoUniformMatrix4fvStreamTextureMatrixCHROMIUM(
             texture_ref->texture()->GetLevelStreamTextureImage(
                 GL_TEXTURE_EXTERNAL_OES, 0)) {
       image->GetTextureMatrix(gl_matrix);
+      GLfloat tmp[16];
+      for (int c = 0; c < 16; c += 4) {
+        for (int r = 0; r < 4; ++r) {

[no sievers, 2016/04/01 21:39:53]

Can you use gfx::Transform for the multiplication?

[no sievers, 2016/04/11 18:08:50]

^^ what about this?

[Tobias Sargeant, 2016/04/12 11:05:24]

I've reimplemented with gfx::Transform. WDYT?

+          tmp[c + r] = 0.0f;
+          for (int i = 0; i < 4; ++i) {
+            tmp[c + r] += gl_matrix[r + 4 * i] * transform[c + i];
+          }
+        }
+      }
+      std::copy(tmp, tmp + 16, gl_matrix);
+    } else {
+      // Missing stream texture. Treat matrix as identity.
+      memcpy(gl_matrix, transform, sizeof(gl_matrix));
     }
   } else {
     LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
@@ -13917,10 +13923,8 @@ void GLES2DecoderImpl::DoCopyTextureCHROMIUM(
     if (GLStreamTextureImage* image =
             source_texture->GetLevelStreamTextureImage(GL_TEXTURE_EXTERNAL_OES,
                                                        0)) {
-      // The coordinate system of this matrix is y-up, not y-down, so a flip is
-      // needed.
       GLfloat transform_matrix[16];
-      image->GetFlippedTextureMatrix(transform_matrix);
+      image->GetTextureMatrix(transform_matrix);
       copy_texture_CHROMIUM_->DoCopyTextureWithTransform(
           this, source_target, source_texture->service_id(), dest_target,
           dest_texture->service_id(), source_width, source_height,
@@ -14111,10 +14115,8 @@ void GLES2DecoderImpl::DoCopySubTextureCHROMIUM(
     if (GLStreamTextureImage* image =
             source_texture->GetLevelStreamTextureImage(GL_TEXTURE_EXTERNAL_OES,
                                                        0)) {
-      // The coordinate system of this matrix is y-up, not y-down, so a flip is
-      // needed.
       GLfloat transform_matrix[16];
-      image->GetFlippedTextureMatrix(transform_matrix);
+      image->GetTextureMatrix(transform_matrix);
       copy_texture_CHROMIUM_->DoCopySubTextureWithTransform(
           this, source_target, source_texture->service_id(),
           source_internal_format, dest_target, dest_texture->service_id(),