Add calls to EnsureGPUMemoryAvailable into GLES2DecoderImpl

gpu/command_buffer/common/gles2_cmd_utils.cc

Index: gpu/command_buffer/common/gles2_cmd_utils.cc
diff --git a/gpu/command_buffer/common/gles2_cmd_utils.cc b/gpu/command_buffer/common/gles2_cmd_utils.cc
index f2513a9267a5152bbb62c86c2cf470cabf9c7698..e0b55793e949c17e27977a32761c5f3768c3e93d 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.cc
+++ b/gpu/command_buffer/common/gles2_cmd_utils.cc
@@ -445,6 +445,23 @@ bool GLES2Util::ComputeImageDataSizes(
   return true;
 }
 
+bool GLES2Util::ComputeEstimatedRenderbufferSize(
+    int width, int height, int samples, int internal_format, uint32* size) {
+  uint32 temp = 0;
+  if (!SafeMultiplyUint32(width, height, &temp)) {
+    return false;
+  }
+  if (!SafeMultiplyUint32(temp, samples, &temp)) {
+    return false;
+  }
+  if (!SafeMultiplyUint32(
+      temp, GLES2Util::RenderbufferBytesPerPixel(internal_format), &temp)) {
+    return false;
+  }
+  *size = temp;
+  return true;
+}
+
 size_t GLES2Util::RenderbufferBytesPerPixel(int format) {
   switch (format) {
     case GL_STENCIL_INDEX8: