Migrate WebGL contexts on backgrounded tabs to the integrated GPU.

gpu/command_buffer/build_gles2_cmd_buffer.py

Index: gpu/command_buffer/build_gles2_cmd_buffer.py
diff --git a/gpu/command_buffer/build_gles2_cmd_buffer.py b/gpu/command_buffer/build_gles2_cmd_buffer.py
index dab6327cdf2d562158d3ffda607241a2b1f4b681..affca5f3f797d23900962e8ed98bcb6666ef483b 100755
--- a/gpu/command_buffer/build_gles2_cmd_buffer.py
+++ b/gpu/command_buffer/build_gles2_cmd_buffer.py
@@ -1792,6 +1792,15 @@ _NAMED_TYPE_INFO = {
       'GL_CONSTANT_CHROMIUM',
     ],
   },
+  'PerformanceHintMode': {
+    'type': 'GLenum',
+    'is_complete': True,
+    'valid': [
+      'GL_DEFAULT_POWER_CHROMIUM',
+      'GL_LOW_POWER_CHROMIUM',
+      'GL_HIGH_PERFORMANCE_CHROMIUM',
+    ],
+  },
   'ReadPixelType': {
     'type': 'GLenum',
     'valid': [
@@ -3491,6 +3500,12 @@ _FUNCTION_INFO = {
     'unit_test': False,
     'es3': True,
   },
+  'PerformanceHintCHROMIUM': {
+    'decoder_func': 'DoPerformanceHintCHROMIUM',
+    'extension': "CHROMIUM_performance_hint",
+    'unit_test': False,
+    'client_test': False,
+  },
   'PixelStorei': {
     'type': 'Custom',
     'impl_func': False,