Add calls to EnsureGPUMemoryAvailable into GLES2DecoderImpl

gpu/command_buffer/service/memory_tracking.h

Index: gpu/command_buffer/service/memory_tracking.h
diff --git a/gpu/command_buffer/service/memory_tracking.h b/gpu/command_buffer/service/memory_tracking.h
index 155ed4b5aa2f219ac97ee95ccb15484176a39515..c89be0fadffa3568bd81b9d27a8b11fabb296468 100644
--- a/gpu/command_buffer/service/memory_tracking.h
+++ b/gpu/command_buffer/service/memory_tracking.h
@@ -25,6 +25,9 @@ class MemoryTracker : public base::RefCounted<MemoryTracker> {
                                            size_t new_size,
                                            Pool pool) = 0;
 
+   // Ensure a certain amount of GPU memory is free. Returns true on success.
+   virtual bool EnsureGPUMemoryAvailable(size_t size_needed) = 0;
+
  protected:
   friend class base::RefCounted<MemoryTracker>;
   MemoryTracker() {}
@@ -67,6 +70,14 @@ class MemoryTypeTracker {
     return mem_represented_at_last_update_;
   }
 
+  // Ensure a certain amount of GPU memory is free. Returns true on success.
+  bool EnsureGPUMemoryAvailable(size_t size_needed) {
+    if (memory_tracker_) {
+      return memory_tracker_->EnsureGPUMemoryAvailable(size_needed);
+    }
+    return true;
+  }
+
  private:
   void UpdateMemRepresented() {
     // Skip redundant updates only if we have already done an update.