The Shader class now support deferred shader compiling.

gpu/command_buffer/service/shader_manager.cc

Index: gpu/command_buffer/service/shader_manager.cc
diff --git a/gpu/command_buffer/service/shader_manager.cc b/gpu/command_buffer/service/shader_manager.cc
index 2707b90b92de4105d6b8c9f1dad28a0663158f0e..4b43aa7843145a7fb615c351a27b64bd1168eb0c 100644
--- a/gpu/command_buffer/service/shader_manager.cc
+++ b/gpu/command_buffer/service/shader_manager.cc
@@ -26,6 +26,7 @@ std::string GetTopVariableName(const std::string& fullname) {
 
 Shader::Shader(GLuint service_id, GLenum shader_type)
       : use_count_(0),
+        shader_state_(kShaderStateWaiting),
         service_id_(service_id),
         shader_type_(shader_type),
         valid_(false) {
@@ -34,13 +35,34 @@ Shader::Shader(GLuint service_id, GLenum shader_type)
 Shader::~Shader() {
 }
 
+void Shader::RequestCompile() {
+  shader_state_ = kShaderStateCompileRequested;
+  last_compiled_source_ = source_;
+}
+
 void Shader::DoCompile(ShaderTranslatorInterface* translator,
                        TranslatedShaderSourceType type) {
+  // If compile was not requested yet, we assume this is not a deferred compile.
+  // It is up to the caller of the function to check that the shader state
+  // is kShaderStateCompileRequested if they want to enforce deferred shader
+  // compiles. Otherwise calling DoCompile() will just compile the source that
+  // was last set. For deferred compiles we should compile
+  // |last_compiled_source_| instead of |source_| because they could have set a
+  // new shader source after requesting a compile, in which case the shader at
+  // the time of the compile request is the proper source.

[vmiura, 2015/02/04 21:18:56]

nit: DCHECK(shader_state_ != kShaderStateCompiled)

[David Yen, 2015/02/04 22:05:49]

After discussing in person, we decided to simplify the API to only support
Compile after RequestCompile.

+  if (shader_state_ != kShaderStateCompileRequested) {
+    last_compiled_source_ = source_;
+  }
+
+  // Signify the shader has been compiled, whether or not it is valid
+  // is dependent on the |valid_| member variable.
+  shader_state_ = kShaderStateCompiled;
+
   // Translate GL ES 2.0 shader to Desktop GL shader and pass that to
   // glShaderSource and then glCompileShader.
-  const char* source_for_driver = source_.c_str();
+  const char* source_for_driver = last_compiled_source_.c_str();
   if (translator) {
-    valid_ = translator->Translate(source_,
+    valid_ = translator->Translate(last_compiled_source_,
                                    &log_info_,
                                    &translated_source_,
                                    &attrib_map_,
@@ -50,7 +72,6 @@ void Shader::DoCompile(ShaderTranslatorInterface* translator,
     if (!valid_) {
       return;
     }
-    signature_source_ = source_;
     source_for_driver = translated_source_.c_str();
   }
 
@@ -88,7 +109,7 @@ void Shader::DoCompile(ShaderTranslatorInterface* translator,
     LOG_IF(ERROR, translator)
         << "Shader translator allowed/produced an invalid shader "
         << "unless the driver is buggy:"
-        << "\n--original-shader--\n" << source_
+        << "\n--original-shader--\n" << last_compiled_source_
         << "\n--translated-shader--\n" << source_for_driver
         << "\n--info-log--\n" << log_info_;
   }